Average Weather in January in Port Saint John Florida, United States
Daily high temperatures are around 70°F, rarely falling below 59°F or exceeding 79°F. The lowest daily average high temperature is 70°F on January 17.
Daily low temperatures are around 53°F, rarely falling below 39°F or exceeding 66°F. The lowest daily average low temperature is 53°F on January 18.
For reference, on August 3, the hottest day of the year, temperatures in Port Saint John typically range from 75°F to 89°F, while on January 18, the coldest day of the year, they range from 53°F to 70°F.
Average High and Low Temperature in January
The figure below shows you a compact characterization of the hourly average temperatures for the quarter of the year centered on January. 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 January
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 month of January in Port Saint John experiences essentially constant cloud cover, with the percentage of time that the sky is overcast or mostly cloudy remaining about 43% throughout the month. The highest chance of overcast or mostly cloudy conditions is 44% on January 4.
The clearest day of the month is January 31, with clear, mostly clear, or partly cloudy conditions 59% of the time.
For reference, on July 6, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 69%, while on May 2, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 65%.
Cloud Cover Categories in January
0% clear 20% mostly clear 40% partly cloudy 60% mostly cloudy 80% overcast 100%
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Port Saint John, the chance of a wet day over the course of January is increasing, starting the month at 18% and ending it at 22%.
For reference, the year's highest daily chance of a wet day is 59% on August 25, and its lowest chance is 16% on November 21.
Probability of Precipitation in January
To show variation within the month and not just the monthly total, we show the rainfall accumulated over a sliding 31-day period centered around each day.
The average sliding 31-day rainfall during January in Port Saint John is gradually increasing, starting the month at 2.1 inches, when it rarely exceeds 4.5 inches or falls below 0.3 inches, and ending the month at 2.4 inches, when it rarely exceeds 4.2 inches or falls below 0.5 inches.
Average Monthly Rainfall in January
Over the course of January in Port Saint John, the length of the day is gradually increasing. From the start to the end of the month, the length of the day increases by 28 minutes, implying an average daily increase of 57 seconds, and weekly increase of 6 minutes, 38 seconds.
The shortest day of the month is January 1, with 10 hours, 22 minutes of daylight and the longest day is January 31, with 10 hours, 51 minutes of daylight.
Hours of Daylight and Twilight in January
The latest sunrise of the month in Port Saint John is 7:16 AM on January 10 and the earliest sunrise is 6 minutes earlier at 7:11 AM on January 31.
The earliest sunset is 5:38 PM on January 1 and the latest sunset is 24 minutes later at 6:02 PM on January 31.
Daylight saving time is observed in Port Saint John during 2021, but it neither starts nor ends during January, so the entire month is in standard time.
For reference, on June 21, the longest day of the year, the Sun rises at 6:26 AM and sets 13 hours, 57 minutes later, at 8:23 PM, while on December 21, the shortest day of the year, it rises at 7:11 AM and sets 10 hours, 20 minutes later, at 5:31 PM.
Sunrise & Sunset with Twilight in January
The figure below presents a compact representation of key lunar data for January 2021. 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 January
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 Port Saint John is decreasing during January, falling from 18% to 10% over the course of the month.
The lowest chance of a muggy day during January is 10% on January 31.
For reference, on July 17, the muggiest day of the year, there are muggy conditions 100% of the time, while on January 31, the least muggy day of the year, there are muggy conditions 10% of the time.
Humidity Comfort Levels in January
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
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 Port Saint John is essentially constant during January, remaining within 0.2 miles per hour of 11.3 miles per hour throughout.
For reference, on March 10, the windiest day of the year, the daily average wind speed is 11.9 miles per hour, while on August 4, the calmest day of the year, the daily average wind speed is 7.3 miles per hour.
Average Wind Speed in January
The hourly average wind direction in Port Saint John throughout January is predominantly from the north, with a peak proportion of 31% on January 25.
Wind Direction in January
Port Saint John 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 Port Saint John is gradually decreasing during January, falling by 2°F, from 72°F to 70°F, over the course of the month.
Average Water Temperature in January
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).
While it does not do so every year, freezing temperatures are seen in Port Saint John over some winters. The day least likely to be in the growing season is January 8, with a 75% chance.
Time Spent in Various Temperature Bands and the Growing Season in January
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
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 Port Saint John are increasing during January, increasing by 341°F, from 0°F to 342°F, over the course of the month.
Growing Degree Days in January
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 Port Saint John is gradually increasing during January, rising by 0.6 kWh, from 3.4 kWh to 4.0 kWh, over the course of the month.
Average Daily Incident Shortwave Solar Energy in January
For the purposes of this report, the geographical coordinates of Port Saint John are 28.477 deg latitude, -80.789 deg longitude, and 23 ft elevation.
The topography within 2 miles of Port Saint John is essentially flat, with a maximum elevation change of 43 feet and an average elevation above sea level of 19 feet. Within 10 miles is also essentially flat (72 feet). Within 50 miles is essentially flat (187 feet).
The area within 2 miles of Port Saint John is covered by artificial surfaces (65%), herbaceous vegetation (18%), and water (14%), within 10 miles by herbaceous vegetation (43%) and artificial surfaces (26%), and within 50 miles by water (46%) and herbaceous vegetation (22%).
This report illustrates the typical weather in Port Saint John, 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 6 weather stations near enough to contribute to our estimation of the temperature and dew point in Port Saint John.
For each station, the records are corrected for the elevation difference between that station and Port Saint John 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 Port Saint John is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Port Saint John and a given station.
The stations contributing to this reconstruction are: NASA Shuttle Facility (37%, 18 kilometers, northeast); Port Canaveral North Heliport (27%, 22 kilometers, east); Patrick Air Force Base (15%, 33 kilometers, southeast); Orlando International Airport (7%, 53 kilometers, west); Executive Airport (7%, 54 kilometers, west); and Orlando Sanford International Airport (7%, 56 kilometers, northwest).
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 © Esri, with data from National Geographic, Esri, DeLorme, NAVTEQ, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, and iPC.
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.