Mount Vernon Northwestern Washington Research & Extension Center

Fruit Horticulture Program

Photo collage of apples, grapes and wine

WSU Mount Vernon Monthly Weather Records

Following is a summary of the weather data collected at the WSU Mount Vernon Research and Extension Center. Column two indicates the time span for which records were used for the summarization.

January through July

Measurement Jan Feb Mar Apr May Jun Jul
Ambient max, Daily Avg for Mo. 1948 -1997 Mean Deg F 44.2 48.4 52.0 56.9 63.4 68.0 72.6
Dry - 1987 Deg F 45.9 48.6 56.7 59.9 64.7 70.6 71.8
Wet - 1971 Deg F 43.2 46.5 48.4 56.8 63.0 63.4 71.1
Ambient min, Daily Avg for Mo. 1948 -1997 Mean Deg F 32.9 35.0 36.8 39.5 44.3 48.5 50.5
Dry - 1987 Deg F 35.5 38.4 40.0 41.6 45.0 48.2 51.1
Wet - 1971 Deg F 34.3 35.9 34.9 38.9 43.1 47.3 48.7
Mean Temperature 1948 -1997 Mean Deg F 38.5 41.7 44.4 48.2 53.9 58.3 61.5
Dry - 1987 Deg F 40.7 43.5 48.4 50.8 54.9 59.4 61.5
Wet - 1971 Deg F 38.8 41.2 41.7 47.9 53.1 55.4 59.9
Rainfall Monthly Total 1948 -1997 Mean Inches 3.95 2.95 2.66 2.48 2.08 1.76 1.17
Dry - 1987 Inches 2.90 2.03 1.65 2.59 2.36 0.90 1.01
Wet - 1971 Inches 10.52 3.01 3.06 2.40 1.82 2.61 1.15
Soil Temp @ 4", Daily Avg for Mo 1948 -1997 Mean Deg F 38.4 40.1 43.5 48.6 55.6 60.9 64.2
Dry - 1987 Deg F 38.7 43.4 47.9 54.2 59.6 63.7 64.4
Wet - 1971 Deg F 39.1 41.5 41.8 48.1 55.4 59.2 64.8
Solar Radiation, Daily Avg for Mo. 1992 -1997 Langley 77 146 252 333 478 510 494
ETO Grass, Daily Avg 1992 -1997 Inches 0.04 0.05 0.08 0.10 0.14 0.15 0.14
Max. daily Temp for the Mo., Avg 1948 -1997 Deg F 56.1 59.0 62.6 69.6 77.6 80.5 84.4
Max. daily Temp for the Mo., Highest 1948 -1997 Deg F 66.0 70.0 72.0 80.0 89.0 92.0 93.0
Min Daily Temp in the Mo., Avg 1948 -1997 Deg F 17.4 22.2 26.5 31.0 35.3 40.7 43.0
Min Daily Temp in the Mo., Lowest 1948 -1997 Deg F -4.0 -2.0 9.0 25.0 28.0 32.0 38.0
Max Daily Rainfall in the Mo., Avg 1948 -1997 Inches 0.85 0.66 0.57 0.58 0.61 0.59 0.53
Max Daily Rainfall in the Mo., Highest 1948 -1997 Inches 2.06 1.46 1.23 1.11 1.45 1.43 1.58

 

August Through December and Yearly Totals

Measurement Aug Sep Oct Nov Dec Avg/Total
Ambient max, Daily Avg for Mo. 1948 -1997 Mean Deg F 73.0 68.2 59.1 50.4 45.3 58.5
Dry - 1987 Deg F 74.8 70.5 63.5 52.9 44.1 60.3
Wet - 1971 Deg F 76.7 63.5 56.1 49.8 41.2 56.6
Ambient min, Daily Avg for Mo. 1948 -1997 Mean Deg F 50.5 46.9 42.1 37.8 34.5 41.6
Dry - 1987 Deg F 49.4 46.6 36.8 42.5 34.1 42.4
Wet - 1971 Deg F 51.9 45.1 41.0 40.8 30.8 41.1
Mean Temperature 1948 -1997 Mean Deg F 61.7 57.5 50.6 44.1 39.9 50.0
Dry - 1987 Deg F 62.1 58.6 50.2 47.7 39.1 51.4
Wet - 1971 Deg F 64.3 54.3 48.6 45.3 36.0 48.9
Rainfall Monthly Total 1948 -1997 Mean Inches 1.39 1.90 3.18 4.33 4.16 32.00
Dry - 1987 Inches 0.54 0.84 0.83 2.04 3.02 20.71
Wet - 1971 Inches 0.85 2.53 3.17 4.75 6.43 42.30
Soil Temp @ 4", Daily Avg for Mo 1948 -1997 Mean Deg F 64.0 59.1 51.9 44.2 39.6 51.0
Dry - 1987 Deg F 63.1 57.8 51.1 46.9 39.2 52.5
Wet - 1971 Deg F 66.5 58.9 51.4 45.1 38.9 50.9
Solar Radiation, Daily Avg for Mo. 1992 -1997 Langley 436 319 162 84 60 279
ETO Grass, Daily Avg 1992 -1997 Inches 0.12 0.08 0.05 0.04 0.04 0.08
Max. daily Temp for the Mo., Avg 1948 -1997 Deg F 84.7 81.0 72.4 60.7 56.2  
Max. daily Temp for the Mo., Highest 1948 -1997 Deg F 98.0 89.0 92.0 71.0 63.0  
Min Daily Temp in the Mo., Avg 1948 -1997 Deg F 42.6 36.9 30.5 25.2 20.1  
Min Daily Temp in the Mo., Lowest 1948 -1997 Deg F 36.0 32.0 24.0 6.0 -1.0  
Max Daily Rainfall in the Mo., Avg 1948 -1997 Inches 0.59 0.67 0.74 0.90 0.95  
Max Daily Rainfall in the Mo., Highest 1948 -1997 Inches 2.42 2.43 1.44 3.01 6.17  
WSU Mount Vernon NWREC, 16650 State Route 536, Mount Vernon, WA 98273, 360-848-6120, FAX 360-848-6159, Contact Us