Precipitation in Williamson trails that of 95% of U.S. towns: 13 inches a year
Midsummer highs settle at about 91°. Only 66° separates winter nights from summer afternoons. Summer afternoons here are warmer than in 81% of U.S. towns. Plan time outside for May, September and October, when highs sit at 74–84°.
A year in Williamson at a glance
Each month’s typical high and low, and what it brings.
What stands out about Williamson’s climate
Compared with towns across the U.S., with Williamson’s place in Arizona beside it.
What a year in Williamson feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 188 frost-free days a year
In half of years the last 32° night comes by April 20 and the first by October 27. Frost and day counts come from NOAA’s station at Prescott Love Fld, AZ, 8 miles from the town’s center, at about the same height.
The 2023 USDA map puts Williamson’s center in zone 7b: the coldest night of a typical winter, averaged over 1991–2020, reaches about 9°. 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 10 inches of snow a winter
Snow, measured at Prescott, AZ, falls mostly in February. Precipitation (rain plus melted snow) adds up to 13 inches a year; August is the wettest month and June the driest. Rain or snow falls on about 63 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Williamson
79% of the work is heating. Months averaging under 55° run from November through April.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Prescott Love Fld, AZ.
Living with Williamson’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
188 frost-free days in zone 7b. The last frost comes by Apr 20 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Oct 27.
Months with highs of 62–84° and lows of 40° or more: May, September and October. 33 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Williamson from natural hazards, river flooding is the largest share (51%); heat waves, cold waves, winter storms and ice storms together are 2%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Williamson and similar climates
TownRatings has no climate map of the towns around Williamson yet.
Climates most like Williamson’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| Williamson, AZ | 26° | 91° | 13" | 10" |
| Spanish Springs, NV | 25° | 91° | 10" | 6.8" |
| Middleton, ID | 24° | 93° | 11" | 9.7" |
| Clarkston Heights-Vineland, WA | 29° | 92° | 13" | 13" |
| Clovis, NM | 24° | 91° | 17" | 13" |
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 Williamson averaged 2.0° warmer than the 1900s. The biggest change is in March (+3.1°).
A bigger shift than in 89% 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 Williamson compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Williamson’s place among Arizona’s.
Williamson weather by month
Highs, lows and precipitation from NOAA’s grid at Williamson’s center; snow, wet days and snow on the ground from Prescott, AZ. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 53° | 26° | 1.2" | 1.9" | 6 | 1 | 35° – 45° |
| February | 56° | 28° | 1.3" | 3.1" | 6 | 1 | 36° – 48° |
| March | 63° | 33° | 1.1" | 2.5" | 5 | 0 | 41° – 54° |
| April | 69° | 37° | 0.5" | 0.4" | 3 | 0 | 47° – 58° |
| May | 78° | 44° | 0.4" | 0.0" | 3 | 0 | 55° – 66° |
| June | 88° | 53° | 0.3" | 0.0" | 2 | 0 | 65° – 76° |
| July | 91° | 61° | 1.9" | 0.0" | 10 | 0 | 73° – 79° |
| August | 88° | 60° | 2.3" | 0.0" | 10 | 0 | 71° – 78° |
| September | 84° | 52° | 1.4" | 0.0" | 6 | 0 | 65° – 71° |
| October | 74° | 41° | 0.8" | 0.0" | 4 | 0 | 53° – 63° |
| November | 62° | 31° | 0.7" | 0.9" | 4 | 0 | 40° – 53° |
| December | 52° | 25° | 1.0" | 1.4" | 5 | 1 | 35° – 43° |
| Year | 72° | 41° | 12.8" | 10.2" | 63 | 4 |
How much a month can swing
A normal is an average. March swings the most: from 1991 to 2020 its average ranged from 41° to 54°. July is the most reliable, staying within 6°.
Where Williamson’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 Williamson’s center.
- Snow: Prescott, AZ.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Prescott Love Fld, AZ, 8 miles from the town’s center, at about the same height; the nearest station that passes our checks for distance, height and agreement with the grid.
- 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 Williamson’s climate
What is the weather like in Williamson?
A typical July afternoon reaches 91°, a January night drops to 26°, and about 10 inches of snow falls in a normal winter. Milder January nights than 65% of U.S. towns; hotter July afternoons than 81% of U.S. towns.
How cold does it get in Williamson in winter?
December nights average 25°. About 113 nights a year reach 32° or below. In the coldest December of the last 30 years the month averaged 35°.
How much snow does Williamson get?
About 10 inches in a normal winter at Prescott, AZ, most of it in February, with snow on the ground about 4 days a year.
How hot does it get in Williamson?
July, with a typical high of 91° and a low of 61°. About 50 days a year reach 90° and 2 reach 100° (Prescott Love Fld, AZ).
When is the first and last frost in Williamson?
In half of years the last spring frost (32°) comes by April 20 and the first fall frost by October 27, about 188 frost-free days, at Prescott Love Fld, AZ.
What growing zone is Williamson in?
Zone 7b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 9°.
What is the best time of year to visit Williamson?
By one simple rule (highs of 62–84° and lows of 40° or more), May, September and October. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Williamson getting warmer?
Yes: 1991–2020 averaged 2.0° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 89% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Williamson.
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.