Bristol Wells Town Site · Photo: David Syzdek · CC BY 2.0Dry weather: only 13 inches of rain and melted snow a year in Mount Wilson, less than in 95% of U.S. towns
On a normal July day the thermometer tops out near 86°. Expect the heaviest rain or snow in February and the lightest in June. Keep the boiler serviced for the months from October to April, which average under 50°.
A year in Mount Wilson at a glance
Each month’s typical high and low, and what it brings.
What stands out about Mount Wilson’s climate
Compared with towns across the U.S., with Mount Wilson’s place in Nevada beside it.
What a year in Mount Wilson feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
A freeze is possible in every month
About 255 nights a year fall to 32° or below, and 19 to 0° or below. Frost and day counts come from Spring Valley Sp, NV, 20 miles away.
The 2023 USDA map puts Mount Wilson’s center in zone 7a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 4°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 13 inches of rain a year
February is the wettest month and June the driest.
Rain + melted snow by month
Inches of water
Heating and cooling a home in Mount Wilson
98% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October through May.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Spring Valley Sp, NV.
Living with Mount Wilson’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
Zone 7a, and frost can come in any month. The longest frost-free stretch in half of years is about 50 days.
Months with highs of 62–84° and lows of 40° or more: May, June, August and September. 9.4 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Mount Wilson from natural hazards, river flooding is the largest share (47%); heat waves, cold waves, winter storms and ice storms together are 2%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Mount Wilson and similar climates
TownRatings has no climate map of the towns around Mount Wilson yet.
Temperatures and precipitation come from NOAA’s 5 km grid; snow and day counts from the stations named on this page.
Warmer than it used to be
The last 30 years in Mount Wilson averaged 1.6° warmer than the 1900s. The biggest change is in January (+2.8°).
A bigger shift than in 64% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How Mount Wilson compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Mount Wilson’s place among Nevada’s.
Mount Wilson weather by month
Highs, lows and precipitation from NOAA’s grid at Mount Wilson’s center. 1991–2020 normals.
| Month | High | Low | Rain + melt | 30-yr range |
|---|---|---|---|---|
| January | 42° | 21° | 1.2" | 26° – 40° |
| February | 44° | 23° | 1.5" | 25° – 41° |
| March | 51° | 28° | 1.4" | 33° – 45° |
| April | 58° | 32° | 1.0" | 39° – 51° |
| May | 68° | 40° | 1.2" | 47° – 59° |
| June | 79° | 50° | 0.6" | 57° – 69° |
| July | 86° | 57° | 1.1" | 68° – 75° |
| August | 84° | 56° | 1.1" | 67° – 74° |
| September | 75° | 47° | 1.0" | 58° – 64° |
| October | 63° | 37° | 1.3" | 43° – 55° |
| November | 50° | 27° | 0.7" | 29° – 45° |
| December | 41° | 21° | 1.1" | 25° – 36° |
| Year | 62° | 36° | 13.2" |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 25° to 41°. September is the most reliable, staying within 6°.
Where Mount Wilson’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at Mount Wilson’s center.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Spring Valley Sp, NV, 20 miles from the town’s center, 660 ft lower; no station nearby passes every check; this is the nearest one in the same valley, flagged above.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about Mount Wilson’s climate
What is the weather like in Mount Wilson?
A typical July afternoon reaches 86°, a January night drops to 21°. Colder January nights than 53% of U.S. towns; hotter July afternoons than 53% of U.S. towns.
How cold does it get in Mount Wilson in winter?
December nights average 21°. About 255 nights a year reach 32° or below and 19 reach 0° or below. In the coldest December of the last 30 years the month averaged 25°.
How hot does it get in Mount Wilson?
July, with a typical high of 86° and a low of 57°. About 32 days a year reach 90° (Spring Valley Sp, NV).
When is the first and last frost in Mount Wilson?
There is no reliable frost-free season: at Spring Valley Sp, NV, every month has nights at 32° or below, about 255 a year. In half of years the longest stretch without a freeze is about 50 days.
What growing zone is Mount Wilson in?
Zone 7a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 4°.
What is the best time of year to visit Mount Wilson?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June, August and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Mount Wilson getting warmer?
Yes: 1991–2020 averaged 1.6° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 64% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Mount Wilson.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.