Average Weather in La Grande Oregon, United States
In La Grande, the summers are short, warm, dry, and mostly clear and the winters are very cold and partly cloudy. Over the course of the year, the temperature typically varies from 25°F to 87°F and is rarely below 9°F or above 96°F.
Based on the tourism score, the best time of year to visit La Grande for warm-weather activities is from early July to mid August.
The hot season lasts for 2.7 months, from June 23 to September 13, with an average daily high temperature above 77°F. The hottest day of the year is August 2, with an average high of 87°F and low of 52°F.
The cold season lasts for 3.4 months, from November 15 to February 25, with an average daily high temperature below 47°F. The coldest day of the year is December 23, with an average low of 25°F and high of 37°F.
Average High and Low Temperature
The figure below shows you a compact characterization of the entire year of hourly average temperatures. The horizontal axis is the day of the year, 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 La Grande, the average percentage of the sky covered by clouds experiences significant seasonal variation over the course of the year.
The clearer part of the year in La Grande begins around June 16 and lasts for 3.6 months, ending around October 5. On July 29, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 82% of the time, and overcast or mostly cloudy 18% of the time.
The cloudier part of the year begins around October 5 and lasts for 8.4 months, ending around June 16. On January 16, the cloudiest day of the year, the sky is overcast or mostly cloudy 66% of the time, and clear, mostly clear, or partly cloudy 34% of the time.
Cloud Cover Categories
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in La Grande varies throughout the year.
The wetter season lasts 7.9 months, from October 23 to June 19, with a greater than 21% chance of a given day being a wet day. The chance of a wet day peaks at 35% on November 28.
The drier season lasts 4.1 months, from June 19 to October 23. The smallest chance of a wet day is 7% on August 2.
Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 29% on May 29.
Daily Chance of Precipitation
To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day of the year. La Grande experiences some seasonal variation in monthly rainfall.
The rainy period of the year lasts for 11 months, from August 19 to July 16, with a sliding 31-day rainfall of at least 0.5 inches. The most rain falls during the 31 days centered around November 23, with an average total accumulation of 1.8 inches.
The rainless period of the year lasts for 1.1 months, from July 16 to August 19. The least rain falls around July 31, with an average total accumulation of 0.4 inches.
Average Monthly Rainfall
We report snowfall in liquid-equivalent terms. The actual depth of new snowfall is typically between 5 and 10 times the liquid-equivalent amount, assuming the ground is frozen. Colder, drier snow tends to be on the higher end of that range and warmer, wetter snow on the lower end.
As with rainfall, we consider the snowfall accumulated over a sliding 31-day period centered around each day of the year. La Grande experiences some seasonal variation in monthly liquid-equivalent snowfall.
The snowy period of the year lasts for 3.6 months, from November 10 to February 26, with a sliding 31-day liquid-equivalent snowfall of at least 0.1 inches. The most snow falls during the 31 days centered around December 28, with an average total liquid-equivalent accumulation of 0.5 inches.
The snowless period of the year lasts for 8.5 months, from February 26 to November 10. The least snow falls around August 2, with an average total liquid-equivalent accumulation of 0.0 inches.
Average Liquid-Equivalent Monthly Snowfall
The length of the day in La Grande varies significantly over the course of the year. In 2018, the shortest day is December 21, with 8 hours, 44 minutes of daylight; the longest day is June 21, with 15 hours, 40 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 5:03 AM on June 15, and the latest sunrise is 2 hours, 31 minutes later at 7:34 AM on November 3. The earliest sunset is at 4:09 PM on December 10, and the latest sunset is 4 hours, 35 minutes later at 8:44 PM on June 26.
Daylight saving time (DST) is observed in La Grande during 2018, starting in the spring on March 11, lasting 7.8 months, and ending in the fall on November 4.
Sunrise & Sunset with Twilight and Daylight Saving Time
The perceived humidity level in La Grande, as measured by the percentage of time in which the humidity comfort level is muggy, oppressive, or miserable, does not vary significantly over the course of the year, remaining a virtually constant 0% throughout.
Humidity Comfort Levels
The average hourly wind speed in La Grande experiences significant seasonal variation over the course of the year.
The windier part of the year lasts for 4.9 months, from October 31 to March 28, with average wind speeds of more than 6.4 miles per hour. The windiest day of the year is December 30, with an average hourly wind speed of 7.9 miles per hour.
The calmer time of year lasts for 7.1 months, from March 28 to October 31. The calmest day of the year is August 11, with an average hourly wind speed of 4.9 miles per hour.
Average Wind Speed
The predominant average hourly wind direction in La Grande varies throughout the year.
The wind is most often from the west for 7.1 months, from March 15 to October 19, with a peak percentage of 58% on June 21. The wind is most often from the south for 4.9 months, from October 19 to March 15, with a peak percentage of 65% on January 1.
Best Time of Year to Visit
To characterize how pleasant the weather is in La Grande throughout the year, we compute two travel scores.
The tourism score favors clear, rainless days with perceived temperatures between 65°F and 80°F. Based on this score, the best time of year to visit La Grande for general outdoor tourist activities is from early July to mid August, with a peak score in the last week of July.
The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best time of year to visit La Grande for hot-weather activities is from mid July to mid August, with a peak score in the first week of August.
For each hour between 8:00 AM and 9:00 PM of each day in the analysis period (1980 to 2016), independent scores are computed for perceived temperature, cloud cover, and total precipitation. Those scores are combined into a single hourly composite score, which is then aggregated into days, averaged over all the years in the analysis period, and smoothed.
Our cloud cover score is 10 for fully clear skies, falling linearly to 9 for mostly clear skies, and to 1 for fully overcast skies.
Our precipitation score, which is based on the three-hour precipitation centered on the hour in question, is 10 for no precipitation, falling linearly to 9 for trace precipitation, and to 0 for 0.04 inches of precipitation or more.
Our tourism temperature score is 0 for perceived temperatures below 50°F, rising linearly to 9 for 65°F, to 10 for 75°F, falling linearly to 9 for 80°F, and to 1 for 90°F or hotter.
Our beach/pool temperature score is 0 for perceived temperatures below 65°F, rising linearly to 9 for 75°F, to 10 for 82°F, falling linearly to 9 for 90°F, and to 1 for 100°F or hotter.
The growing season in La Grande typically lasts for 4.5 months (137 days), from around May 10 to around September 24, rarely starting before April 22 or after May 30, and rarely ending before September 6 or after October 13.
Time Spent in Various Temperature Bands and the Growing Season
Based on growing degree days alone, the first spring blooms in La Grande should appear around April 24, only rarely appearing before April 7 or after May 11.
Growing Degree Days
The average daily incident shortwave solar energy experiences extreme seasonal variation over the course of the year.
The brighter period of the year lasts for 3.0 months, from May 22 to August 23, with an average daily incident shortwave energy per square meter above 6.5 kWh. The brightest day of the year is July 13, with an average of 7.8 kWh.
The darker period of the year lasts for 3.6 months, from October 28 to February 16, with an average daily incident shortwave energy per square meter below 2.6 kWh. The darkest day of the year is December 20, with an average of 1.4 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of La Grande are 45.325 deg latitude, -118.088 deg longitude, and 2,841 ft elevation.
The topography within 2 miles of La Grande contains very significant variations in elevation, with a maximum elevation change of 1,263 feet and an average elevation above sea level of 2,932 feet. Within 10 miles contains very significant variations in elevation (3,428 feet). Within 50 miles also contains extreme variations in elevation (9,160 feet).
The area within 2 miles of La Grande is covered by shrubs (41%), cropland (24%), artificial surfaces (22%), and grassland (13%), within 10 miles by shrubs (47%) and cropland (34%), and within 50 miles by shrubs (45%) and trees (33%).
This report illustrates the typical weather in La Grande, 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 La Grande.
For each station, the records are corrected for the elevation difference between that station and La Grande 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 La Grande is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between La Grande and a given station.
Time zones for aiports and weather stations are provided by AskGeo.com .