Average Weather In July For Salem, Oregon, USA

Location

This report describes the typical weather at the McNary Field (Salem, Oregon, United States) weather station over the course of an average July. It is based on the historical records from 1974 to 2012. Earlier records are either unavailable or unreliable.

Salem, Oregon has a mediterranean climate with dry warm summers and mild winters. The area within 25 mi of this station is covered by forests (54%) and croplands (43%).

Temperature

The month of July is characterized by rising daily high temperatures, with daily highs ranging from 77°F to 83°F over the course of the month, exceeding 94°F or dropping below 67°F only one day in ten.

Daily High and Low Temperature in July

The daily average low (blue) and high (red) temperature with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile).
Daily low temperatures are around 54°F, falling below 47°F or exceeding 60°F only one day in ten.

Fraction of Time Spent in Various Temperature Bands in July

The average fraction of time spent in various temperature bands: frigid (below 15°F), freezing (15°F to 32°F), cold (32°F to 50°F), cool (50°F to 65°F), comfortable (65°F to 75°F), warm (75°F to 85°F), hot (85°F to 100°F) and sweltering (above 100°F).

Sun

Over the course of July, the length of the day is gradually decreasing. From the start to the end of the month, the length of the day decreases by 50 minutes, implying an average day-over-day decrease of 1.6 minutes.

The shortest day of the month is July 31 with 14:42 hours of daylight; the longest day is July 1 with 15:32 hours of daylight.

Daily Hours of Daylight and Twilight in July

The number of hours during which the Sun is visible (black line), with various degrees of daylight, twilight, and night, indicated by the color bands. From bottom (most yellow) to top (most gray): full daylight, solar twilight (Sun is visible but less than 6° from the horizon), civil twilight (Sun is not visible but is less than 6° below the horizon), nautical twilight (Sun is between 6° and 12° below the horizon), astronomical twilight (Sun is between 12° and 18° below the horizon), and full night.

The earliest sunrise is at 5:30am on July 1; the latest sunset is at 9:02pm on July 3; the latest sunrise is at 5:57am on July 31; the earliest sunset is at 8:39pm on July 31.

Daylight savings time is observed in 2012 but it neither starts nor ends in July, so the entire month is in daylight time.

Daily Sunrise & Sunset with Twilight and Daylight Savings Time in July

The solar day over the course of the year 2012 . From bottom to top, the black lines are the previous solar midnight, sunrise, solar noon, sunset, and the next solar midnight. The day, twilights (solar, civil, nautical, and astronomical), and night are indicated by the color bands from yellow to gray. The transitions to and from daylight savings time are indicated by the "DST" labels.

Clouds

The median cloud cover ranges from 17% (mostly clear) to 38% (mostly clear). The trend is for the sky to be clearing rapidly with the median cloud cover decreasing by 21% from the start to the end of the month.

Median Cloud Cover in July

The median daily cloud cover (black line) with percentile bands (inner band from 40th to 60th percentile, outer band from 25th to 75th percentile).

On July 31, the clearest day of the month, the sky is clear, mostly clear, or partly cloudy 74% of the time, and overcast or mostly cloudy 26% of the time.

On July 1, the cloudiest day of the month, the sky is overcast, mostly cloudy, or partly cloudy 49% of the time, and clear or mostly clear 51% of the time.

Cloud Cover Types in July

The fraction of time spent in each of the five sky cover categories. From top (most blue) to bottom (most gray), the categories are clear, mostly clear, partly cloudy, mostly cloudy, and overcast. Pink indicates missing data. Outside of the United States clear skies are often reported ambiguously, leading them to be lumped in with the missing data.

Precipitation

The probability that precipitation will be observed at this location varies throughout the month. Precipitation is most likely around July 1, occurring in 25% of days. Precipitation is least likely around July 29, occurring in 16% of days.

Probability of Precipitation at Some Point in the Day in July

The fraction of days in which various types of precipitation are observed. If more than one type of precipitation is reported in a given day, the more severe precipitation is counted. For example, if light rain is observed in the same day as a thunderstorm, that day counts towards the thunderstorm totals. The order of severity is from the top down in this graph, with the most severe at the bottom.

Throughout July, the most common forms of precipitation are light rain, moderate rain, and thunderstorms.

Light rain is the most severe precipitation observed during 58% of those days with precipitation. It is most likely around July 1, when it is observed during 15% of all days.

Moderate rain is the most severe precipitation observed during 21% of those days with precipitation. It is most likely around July 1, when it is observed during 6% of all days.

Thunderstorms are the most severe precipitation observed during 12% of those days with precipitation. They are most likely around July 28, when it is observed during 2% of all days.

Types of Precipitation Throughout July

Relative frequency of various types of precipitation over the course of a typical July.

Snow

Either snow is exceptionally unlikely to fall at this location in July or this station does not reliably report precipitation types.

Humidity

The relative humidity typically ranges from 35% (comfortable) to 90% (very humid) over the course of a typical July, rarely dropping below 22% (dry) and reaching as high as 99% (very humid).

The air is driest around July 31, at which time the relative humidity drops below 41% (comfortable) three days out of four; it is most humid around July 1, rising above 86% (very humid) three days out of four.

Relative Humidity in July

The average daily high (blue) and low (brown) relative humidity with percentile bands (inner bands from 25th to 75th percentile, outer bands from 10th to 90th percentile).

Dew Point

Dew point is often a better measure of how comfortable a person will find the weather than relative humidity because it more directly relates to whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid.

Over the course of a typical July, the dew point typically varies from 46°F (dry) to 57°F (comfortable) and is rarely below 41°F (dry) or above 61°F (comfortable).

The time of the month between July 1 and July 31 is the most comfortable, with dew points that are neither too dry nor too muggy.

Dew Point in July

The daily average low (blue) and high (red) dew point with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile).

Wind

Over the course of July typical wind speeds vary from 0 mph to 13 mph (calm to moderate breeze), rarely exceeding 16 mph (moderate breeze).

The highest average wind speed of 7 mph (light breeze) occurs around July 15, at which time the average daily maximum wind speed is 13 mph (moderate breeze).

The lowest average wind speed of 6 mph (light breeze) occurs around July 30, at which time the average daily maximum wind speed is 13 mph (moderate breeze).

Wind Speed in July

The average daily minimum (red), maximum (green), and average (black) wind speed with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile).
The wind is most often out of the south (26% of the time) and north (15% of the time). The wind is least often out of the east (2% of the time) and north east (5% of the time).

Wind Directions in July

The fraction of time spent with the wind blowing from the various directions over the entire year. Values do not sum to 100% because the wind direction is undefined when the wind speed is zero.

Fraction of Time Spent with Various Wind Directions in July

The fraction of time spent with the wind blowing from the various directions on a daily basis. Stacked values do not always sum to 100% because the wind direction is undefined when the wind speed is zero.