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Fall Weather in St Mary's United Kingdom

Daily high temperatures decrease by 12°F, from 64°F to 52°F, rarely falling below 48°F or exceeding 68°F.

Daily low temperatures decrease by 10°F, from 58°F to 48°F, rarely falling below 43°F or exceeding 61°F.

For reference, on August 5, the hottest day of the year, temperatures in St Mary's typically range from 59°F to 66°F, while on February 18, the coldest day of the year, they range from 44°F to 49°F.

Average High and Low Temperature in the Fall in St Mary's

Average High and Low Temperature in the Fall in St Mary'sSepOctNov40°F40°F45°F45°F50°F50°F55°F55°F60°F60°F65°F65°F70°F70°FSummerWinterSep 164°FSep 164°F58°F58°FNov 3052°FNov 3052°F48°F48°FOct 160°FOct 160°F55°F55°FNov 156°FNov 156°F51°F51°F
The daily average high (red line) and low (blue line) temperature, with 25th to 75th and 10th to 90th percentile bands. The thin dotted lines are the corresponding average perceived temperatures.

The figure below shows you a compact characterization of the hourly average fall temperatures. The horizontal axis is the day, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.

Average Hourly Temperature in the Fall in St Mary's

Average Hourly Temperature in the Fall in St Mary'sSepOctNov12 AM12 AM2 AM2 AM4 AM4 AM6 AM6 AM8 AM8 AM10 AM10 AM12 PM12 PM2 PM2 PM4 PM4 PM6 PM6 PM8 PM8 PM10 PM10 PM12 AM12 AMSummerWintercoldcoolcomfortable
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
The average hourly temperature, color coded into bands. The shaded overlays indicate night and civil twilight.

Port Orford, Oregon, United States (5,035 miles away) and Upper Hutt, New Zealand (11,840 miles) are the far-away foreign places with temperatures most similar to St Mary's (view comparison).

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The fall in St Mary's experiences rapidly increasing cloud cover, with the percentage of time that the sky is overcast or mostly cloudy increasing from 51% to 63%.

The clearest day of the fall is September 8, with clear, mostly clear, or partly cloudy conditions 49% of the time.

For reference, on December 24, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 66%, while on August 19, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 52%.

Cloud Cover Categories in the Fall in St Mary's

Cloud Cover Categories in the Fall in St Mary'sSepOctNov0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%SummerWinterSep 149%Sep 149%Nov 3037%Nov 3037%Oct 144%Oct 144%Nov 139%Nov 139%clearmostly clearpartly cloudymostly cloudyovercast
0% clear 20% mostly clear 40% partly cloudy 60% mostly cloudy 80% overcast 100%
The percentage of time spent in each cloud cover band, categorized by the percentage of the sky covered by clouds.

A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In St Mary's, the chance of a wet day over the course of the fall is very rapidly increasing, starting the season at 25% and ending it at 41%.

For reference, the year's highest daily chance of a wet day is 44% on January 6, and its lowest chance is 22% on July 23.

Probability of Precipitation in the Fall in St Mary's

Probability of Precipitation in the Fall in St Mary'sSepOctNov0%0%5%5%10%10%15%15%20%20%25%25%30%30%35%35%40%40%45%45%SummerWinterSep 125%Sep 125%Nov 3041%Nov 3041%Oct 132%Oct 132%Nov 141%Nov 141%rain
The percentage of days in which various types of precipitation are observed, excluding trace quantities: rain alone, snow alone, and mixed (both rain and snow fell in the same day).

Rainfall

To show variation within the season and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day.

The average sliding 31-day rainfall during the fall in St Mary's is rapidly increasing, starting the season at 1.7 inches, when it rarely exceeds 3.2 inches or falls below 0.5 inches, and ending the season at 3.1 inches, when it rarely exceeds 5.0 inches or falls below 1.5 inches.

Average Monthly Rainfall in the Fall in St Mary's

Average Monthly Rainfall in the Fall in St Mary'sSepOctNov0 in0 in1 in1 in2 in2 in3 in3 in4 in4 in5 in5 in6 in6 inSummerWinterSep 11.7 inSep 11.7 inNov 303.1 inNov 303.1 inOct 12.6 inOct 12.6 inNov 13.1 inNov 13.1 in
The average rainfall (solid line) accumulated over the course of a sliding 31-day period centered on the day in question, with 25th to 75th and 10th to 90th percentile bands. The thin dotted line is the corresponding average snowfall.

Over the course of the fall in St Mary's, the length of the day is very rapidly decreasing. From the start to the end of the season, the length of the day decreases by 5 hours, 1 minute, implying an average daily decrease of 3 minutes, 21 seconds, and weekly decrease of 23 minutes, 25 seconds.

The shortest day of the fall is November 30, with 8 hours, 26 minutes of daylight and the longest day is September 1, with 13 hours, 27 minutes of daylight.

Hours of Daylight and Twilight in the Fall in St Mary's

Hours of Daylight and Twilight in the Fall in St Mary'sSepOctNov0 hr24 hr4 hr20 hr8 hr16 hr12 hr12 hr16 hr8 hr20 hr4 hr24 hr0 hrSummerWinterSep 2212 hr, 10 minSep 2212 hr, 10 minnightnightdaydayNov 308 hr, 26 minNov 308 hr, 26 minNov 19 hr, 46 minNov 19 hr, 46 min
The number of hours during which the Sun is visible (black line). From bottom (most yellow) to top (most gray), the color bands indicate: full daylight, twilight (civil, nautical, and astronomical), and full night.

The earliest sunrise of the fall in St Mary's is 6:40 AM on September 1 and the latest sunrise is 1 hour, 25 minutes later at 8:05 AM on October 26.

The latest sunset is 8:08 PM on September 1 and the earliest sunset is 3 hours, 41 minutes earlier at 4:26 PM on November 30.

Daylight saving time (DST) starts at 1:00 AM on October 27, 2024, shifting sunrise and sunset to be an hour later.

For reference, on June 20, the longest day of the year, the Sun rises at 5:16 AM and sets 16 hours, 21 minutes later, at 9:37 PM, while on December 21, the shortest day of the year, it rises at 8:20 AM and sets 8 hours, 5 minutes later, at 4:26 PM.

Sunrise & Sunset with Twilight and Daylight Saving Time in the Fall in St Mary's

Sunrise & Sunset with Twilight and Daylight Saving Time in the Fall in St Mary'sSepOctNov2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AMSummerWinter6:40 AM6:40 AMSep 18:08 PMSep 18:08 PM8:00 AM8:00 AMNov 304:26 PMNov 304:26 PM8:05 AM8:05 AMOct 266:12 PMOct 266:12 PM7:25 AM7:25 AMOct 17:02 PMOct 17:02 PMDSTOct 27DSTOct 27SolarMidnightSolarMidnightSolarNoonSunriseSunset
The solar day in the fall. From bottom to top, the black lines are the previous solar midnight, sunrise, solar noon, sunset, and the next solar midnight. The day, twilights (civil, nautical, and astronomical), and night are indicated by the color bands from yellow to gray. The transitions to and from daylight saving time are indicated by the 'DST' labels.

The figure below presents a compact representation of the sun's elevation (the angle of the sun above the horizon) and azimuth (its compass bearing) for every hour of every day in the reporting period. The horizontal axis is the day of the year and the vertical axis is the hour of the day. For a given day and hour of that day, the background color indicates the azimuth of the sun at that moment. The black isolines are contours of constant solar elevation.

Solar Elevation and Azimuth in the Fall in St Mary's

Solar Elevation and Azimuth in the Fall in St Mary'sSepOctNov12 AM12 AM2 AM2 AM4 AM4 AM6 AM6 AM8 AM8 AM10 AM10 AM12 PM12 PM2 PM2 PM4 PM4 PM6 PM6 PM8 PM8 PM10 PM10 PM12 AM12 AMSummerWinter0020300010103040
northeastsouthwest
Solar elevation and azimuth in the the fall of 2024. The black lines are lines of constant solar elevation (the angle of the sun above the horizon, in degrees). The background color fills indicate the azimuth (the compass bearing) of the sun. The lightly tinted areas at the boundaries of the cardinal compass points indicate the implied intermediate directions (northeast, southeast, southwest, and northwest).

The figure below presents a compact representation of key lunar data for the fall of 2024. The horizontal axis is the day, the vertical axis is the hour of the day, and the colored areas indicate when the moon is above the horizon. The vertical gray bars (new Moons) and blue bars (full Moons) indicate key Moon phases. The label associated with each bar indicates the date and time that the phase is obtained, and the companion time labels indicate the rise and set times of the Moon for the nearest time interval in which the moon is above the horizon.

Moon Rise, Set & Phases in the Fall in St Mary's

Moon Rise, Set & Phases in the Fall in St Mary'sSepOctNov12 AM12 AM4 AM4 AM8 AM8 AM12 PM12 PM4 PM4 PM8 PM8 PM12 AM12 AMSummerWinterAug 412:14 PMAug 412:14 PMAug 197:26 PMAug 197:26 PMSep 32:56 AMSep 32:56 AMSep 183:35 AMSep 183:35 AMOct 27:50 PMOct 27:50 PMOct 1712:27 PMOct 1712:27 PMNov 112:48 PMNov 112:48 PMNov 159:29 PMNov 159:29 PMDec 16:22 AMDec 16:22 AMDec 159:02 AMDec 159:02 AMDec 3010:28 PMDec 3010:28 PM9:32 PM9:32 PM8:51 PM8:51 PM6:57 AM6:57 AM6:52 AM6:52 AM8:22 PM8:22 PM7:28 PM7:28 PM7:21 AM7:21 AM6:52 PM6:52 PM6:02 PM6:02 PM7:44 AM7:44 AM7:16 AM7:16 AM4:40 PM4:40 PM4:01 PM4:01 PM8:44 AM8:44 AM8:42 AM8:42 AM4:00 PM4:00 PM8:37 AM8:37 AM3:34 PM3:34 PM
The time in which the moon is above the horizon (light blue area), with new moons (dark gray lines) and full moons (blue lines) indicated. The shaded overlays indicate night and civil twilight.

We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.

The chance that a given day will be muggy in St Mary's is essentially constant during the fall, remaining around 0% throughout.

For reference, on August 8, the muggiest day of the year, there are muggy conditions 1% of the time, while on January 1, the least muggy day of the year, there are muggy conditions 0% of the time.

Humidity Comfort Levels in the Fall in St Mary's

Humidity Comfort Levels in the Fall in St Mary'sSepOctNov0%0%10%10%20%20%30%30%40%40%50%50%60%60%70%70%80%80%90%90%100%100%SummerWinterSep 10%Sep 10%Nov 300%Nov 300%Oct 10%Oct 10%Nov 10%Nov 10%humidhumidcomfortablecomfortabledrydry
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
The percentage of time spent at various humidity comfort levels, categorized by dew point.

This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.

The average hourly wind speed in St Mary's is very rapidly increasing during the fall, increasing from 14.9 miles per hour to 20.5 miles per hour over the course of the season.

For reference, on December 31, the windiest day of the year, the daily average wind speed is 21.8 miles per hour, while on August 3, the calmest day of the year, the daily average wind speed is 13.6 miles per hour.

Average Wind Speed in the Fall in St Mary's

Average Wind Speed in the Fall in St Mary'sSepOctNov0 mph0 mph5 mph5 mph10 mph10 mph15 mph15 mph20 mph20 mph25 mph25 mph30 mph30 mphSummerWinterSep 114.9 mphSep 114.9 mphNov 3020.5 mphNov 3020.5 mphOct 116.4 mphOct 116.4 mphNov 119.1 mphNov 119.1 mph
The average of mean hourly wind speeds (dark gray line), with 25th to 75th and 10th to 90th percentile bands.

The hourly average wind direction in St Mary's throughout the fall is predominantly from the west, with a peak proportion of 39% on September 1.

Wind Direction in the Fall in St Mary's

Wind Direction in the Fall in St Mary'sSepOctNov0%100%20%80%40%60%60%40%80%20%100%0%SummerWinterwestsoutheastnorth
northeastsouthwest
The percentage of hours in which the mean wind direction is from each of the four cardinal wind directions, excluding hours in which the mean wind speed is less than 1.0 mph. The lightly tinted areas at the boundaries are the percentage of hours spent in the implied intermediate directions (northeast, southeast, southwest, and northwest).

St Mary's is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.

The average surface water temperature in St Mary's is rapidly decreasing during the fall, falling by 8°F, from 62°F to 53°F, over the course of the season.

Average Water Temperature in the Fall in St Mary's

Average Water Temperature in the Fall in St Mary'sSepOctNov48°F48°F50°F50°F52°F52°F54°F54°F56°F56°F58°F58°F60°F60°F62°F62°F64°F64°F66°F66°FSummerWinterSep 162°FSep 162°FNov 3053°FNov 3053°FOct 159°FOct 159°FNov 156°FNov 156°F
The daily average water temperature (purple line), with 25th to 75th and 10th to 90th percentile bands.

Definitions of the growing season vary throughout the world, but for the purposes of this report, we define it as the longest continuous period of non-freezing temperatures (≥ 32°F) in the year (the calendar year in the Northern Hemisphere, or from July 1 until June 30 in the Southern Hemisphere).

Temperatures in St Mary's are sufficiently warm year round that it is not entirely meaningful to discuss the growing season in these terms. We nevertheless include the chart below as an illustration of the distribution of temperatures experienced throughout the year.

Time Spent in Various Temperature Bands and the Growing Season in the Fall in St Mary's

Time Spent in Various Temperature Bands and the Growing Season in the Fall in St Mary'sSepOctNov0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%SummerWinter100%Oct 16100%Oct 16very coldcoldcoolcomfortable
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
The percentage of time spent in various temperature bands. The black line is the percentage chance that a given day is within the growing season.

Growing degree days are a measure of yearly heat accumulation used to predict plant and animal development, and defined as the integral of warmth above a base temperature, discarding any excess above a maximum temperature. In this report, we use a base of 50°F and a cap of 86°F.

The average accumulated growing degree days in St Mary's are rapidly increasing during the fall, increasing by 533°F, from 1,153°F to 1,686°F, over the course of the season.

Growing Degree Days in the Fall in St Mary's

Growing Degree Days in the Fall in St Mary'sSepOctNov1,000°F1,000°F1,200°F1,200°F1,400°F1,400°F1,600°F1,600°F1,800°F1,800°FSummerWinterSep 11,153°FSep 11,153°FNov 301,686°FNov 301,686°FOct 11,435°FOct 11,435°FNov 11,611°FNov 11,611°F
The average growing degree days accumulated over the course of the fall, with 25th to 75th and 10th to 90th percentile bands.

This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.

The average daily incident shortwave solar energy in St Mary's is very rapidly decreasing during the fall, falling by 3.7 kWh, from 4.6 kWh to 0.9 kWh, over the course of the season.

Average Daily Incident Shortwave Solar Energy in the Fall in St Mary's

Average Daily Incident Shortwave Solar Energy in the Fall in St Mary'sSepOctNov0 kWh0 kWh1 kWh1 kWh2 kWh2 kWh3 kWh3 kWh4 kWh4 kWh5 kWh5 kWh6 kWh6 kWh7 kWh7 kWh8 kWh8 kWhSummerWinterSep 14.6 kWhSep 14.6 kWhNov 300.9 kWhNov 300.9 kWhOct 13.0 kWhOct 13.0 kWhNov 11.6 kWhNov 11.6 kWh
The average daily shortwave solar energy reaching the ground per square meter (orange line), with 25th to 75th and 10th to 90th percentile bands.

For the purposes of this report, the geographical coordinates of St Mary's are 49.917 deg latitude, -6.295 deg longitude, and 46 ft elevation.

The topography within 2 miles of St Mary's contains only modest variations in elevation, with a maximum elevation change of 171 feet and an average elevation above sea level of 16 feet. Within 10 miles also contains only modest variations in elevation (174 feet). Within 50 miles contains only modest variations in elevation (827 feet).

The area within 2 miles of St Mary's is covered by water (80%) and cropland (11%), within 10 miles by water (99%), and within 50 miles by water (97%).

This report illustrates the typical weather in St Mary's, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.

Temperature and Dew Point

There are 2 weather stations near enough to contribute to our estimation of the temperature and dew point in St Mary's.

For each station, the records are corrected for the elevation difference between that station and St Mary's according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations.

The estimated value at St Mary's is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between St Mary's and a given station.

The stations contributing to this reconstruction are:

To get a sense of how much these sources agree with each other, you can view a comparison of St Mary's and the stations that contribute to our estimates of its temperature history and climate. Please note that each source's contribution is adjusted for elevation and the relative change present in the MERRA-2 data.

Other Data

All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Algorithms 2nd Edition , by Jean Meeus.

All other weather data, including cloud cover, precipitation, wind speed and direction, and solar flux, come from NASA's MERRA-2 Modern-Era Retrospective Analysis . This reanalysis combines a variety of wide-area measurements in a state-of-the-art global meteorological model to reconstruct the hourly history of weather throughout the world on a 50-kilometer grid.

Land Use data comes from the Global Land Cover SHARE database , published by the Food and Agriculture Organization of the United Nations.

Elevation data comes from the Shuttle Radar Topography Mission (SRTM) , published by NASA's Jet Propulsion Laboratory.

Names, locations, and time zones of places and some airports come from the GeoNames Geographical Database .

Time zones for airports and weather stations are provided by AskGeo.com .

Maps are © OpenStreetMap contributors.

Disclaimer

The information on this site is provided as is, without any assurances as to its accuracy or suitability for any purpose. Weather data is prone to errors, outages, and other defects. We assume no responsibility for any decisions made on the basis of the content presented on this site.

We draw particular cautious attention to our reliance on the MERRA-2 model-based reconstructions for a number of important data series. While having the tremendous advantages of temporal and spatial completeness, these reconstructions: (1) are based on computer models that may have model-based errors, (2) are coarsely sampled on a 50 km grid and are therefore unable to reconstruct the local variations of many microclimates, and (3) have particular difficulty with the weather in some coastal areas, especially small islands.

We further caution that our travel scores are only as good as the data that underpin them, that weather conditions at any given location and time are unpredictable and variable, and that the definition of the scores reflects a particular set of preferences that may not agree with those of any particular reader.

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