Teapot Dome Service Station · Photo: Iflorea · CC BY-SA 4.0Zillah is among the driest of U.S. towns: 8 inches of precipitation a year
January mornings start at about 27°. Summer afternoons here are warmer than in 78% of U.S. towns. The latest 30-year average runs 1.0° warmer than 1901–2000’s, with January up the most. If you like long walks, May, June and September offer highs of 74–81°.
A year in Zillah at a glance
Each month’s typical high and low, and what it brings.
What stands out about Zillah’s climate
Compared with towns across the U.S., with Zillah’s place in Washington beside it.
What a year in Zillah feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 176 frost-free days a year
In half of years the last 32° night comes by April 21 and the first by October 15. Frost and day counts come from NOAA’s station at Wapato, WA, 7 miles from the town’s center, at about the same height.
The 2023 USDA map puts Zillah’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 20 inches of snow a winter
Snow, measured at Wapato, WA, falls mostly in December. Precipitation (rain plus melted snow) adds up to 8 inches a year; December is the wettest month and July the driest. Rain or snow falls on about 68 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Zillah
87% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October 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 Wapato, WA.
Living with Zillah’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
176 frost-free days in zone 7a. The last frost comes by Apr 21 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 15.
Months with highs of 62–84° and lows of 40° or more: May, June and September. 1.1 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Zillah from natural hazards, river flooding is the largest share (60%); heat waves, cold waves, winter storms and ice storms together are 15%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Zillah and similar climates
TownRatings has no climate map of the towns around Zillah yet.
Climates most like Zillah’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 |
|---|---|---|---|---|
| Zillah, WA | 27° | 90° | 8" | 20" |
| Gardnerville Ranchos, NV | 23° | 90° | 11" | 22" |
| Twin Falls, ID | 22° | 90° | 10" | 24" |
| Williamson, AZ | 26° | 91° | 13" | 10" |
| Ontario, OR | 23° | 93° | 10" | 15" |
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 Zillah averaged 1.0° warmer than the 1900s. The biggest change is in January (+3.3°).
A smaller shift than in 79% 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 Zillah compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Zillah’s place among Washington’s.
Zillah weather by month
Highs, lows and precipitation from NOAA’s grid at Zillah’s center; snow, wet days and snow on the ground from Wapato, WA. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | 30-yr range |
|---|---|---|---|---|---|---|
| January | 40° | 27° | 1.0" | 5.2" | 9 | 24° – 38° |
| February | 47° | 28° | 0.7" | 1.1" | 6 | 25° – 44° |
| March | 57° | 33° | 0.6" | 0.3" | 6 | 37° – 51° |
| April | 65° | 39° | 0.7" | 0.0" | 5 | 47° – 58° |
| May | 74° | 47° | 0.8" | 0.0" | 6 | 55° – 67° |
| June | 81° | 53° | 0.6" | 0.0" | 5 | 63° – 75° |
| July | 90° | 59° | 0.2" | 0.0" | 3 | 66° – 79° |
| August | 89° | 57° | 0.2" | 0.0" | 2 | 67° – 77° |
| September | 80° | 49° | 0.3" | 0.0" | 3 | 60° – 68° |
| October | 65° | 38° | 0.8" | 0.2" | 6 | 46° – 58° |
| November | 50° | 31° | 0.9" | 1.6" | 8 | 34° – 47° |
| December | 39° | 26° | 1.2" | 12.0" | 10 | 26° – 38° |
| Year | 65° | 40° | 7.9" | 20.4" | 68 |
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 44°. September is the most reliable, staying within 8°.
Where Zillah’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 Zillah’s center.
- Snow: Wapato, WA.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Wapato, WA, 7 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 Zillah’s climate
What is the weather like in Zillah?
A typical July afternoon reaches 90°, a January night drops to 27°, and about 20 inches of snow falls in a normal winter. Milder January nights than 67% of U.S. towns; hotter July afternoons than 78% of U.S. towns.
How cold does it get in Zillah in winter?
December nights average 26°. About 127 nights a year reach 32° or below and 1 reach 0° or below. In the coldest December of the last 30 years the month averaged 26°.
How much snow does Zillah get?
About 20 inches in a normal winter at Wapato, WA, most of it in December.
How hot does it get in Zillah?
July, with a typical high of 90° and a low of 59°. About 41 days a year reach 90° and 4 reach 100° (Wapato, WA).
When is the first and last frost in Zillah?
In half of years the last spring frost (32°) comes by April 21 and the first fall frost by October 15, about 176 frost-free days, at Wapato, WA.
What growing zone is Zillah 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 Zillah?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Zillah getting warmer?
Yes: 1991–2020 averaged 1.0° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 79% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Zillah.
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.