WSU Mount Vernon Monthly Weather Records
Following is a summary of the weather data collected at WSU Mount Vernon.
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 |