Photo: formulanone from Huntsville, United States · CC BY-SA 2.0Kennewick is among the driest of U.S. towns: 8 inches of precipitation a year
The coldest hours of a January night bottom out at 29° on average. From frosty January to warm July, readings climb 62°. By July afternoons alone, it runs hotter than 77% of U.S. towns. Picnics, hikes and garden evenings suit May, June, September and October, with highs of 65–81°.
A year in Kennewick at a glance
Each month’s typical high and low, and what it brings.
What stands out about Kennewick’s climate
Compared with towns across the U.S., with Kennewick’s place in Washington beside it.
What a year in Kennewick feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 216 frost-free days a year
In half of years the last 32° night comes by March 28 and the first by October 30. Frost and day counts come from NOAA’s station at Kennewick, WA, 4 miles from the city’s center point, 150 ft lower.
The 2023 USDA map puts Kennewick’s center in zone 7b: the coldest night of a typical winter, averaged over 1991–2020, reaches about 6°. 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 2 inches of snow a winter
Snow, measured at Ice Harbor Dam, WA, falls mostly in December. Precipitation (rain plus melted snow) adds up to 8 inches a year; December is the wettest month and August the driest. Rain or snow falls on about 97 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Kennewick
82% of the work is heating. 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 Kennewick, WA.
Living with Kennewick’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
216 frost-free days in zone 7b. The last frost comes by Mar 28 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 30.
Months with highs of 62–84° and lows of 40° or more: May, June, September and October. 39 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Kennewick from natural hazards, river flooding is the largest share (57%); heat waves, cold waves, winter storms and ice storms together are 18%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Kennewick and its neighbors
Every town next door is within a degree of Kennewick in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Kennewick’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 |
|---|---|---|---|---|
| Kennewick, WA | 29° | 90° | 8" | 2.0" |
| Alpine, TX | 30° | 90° | 15" | 2.2" |
| Spanish Springs, NV | 25° | 91° | 10" | 6.8" |
| Sierra Vista, AZ | 32° | 91° | 14" | 0.4" |
| Alamogordo, NM | 27° | 93° | 11" | 2.4" |
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value. Snow and frost-free days come from the nearest weather station, so neighbors often share them.
Warmer than it used to be
The last 30 years in Kennewick averaged 1.0° warmer than the 1900s. The biggest change is in January (+3.6°).
A smaller shift than in 75% 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 Kennewick compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Kennewick’s place among Washington’s.
Kennewick weather by month
Highs, lows and precipitation from NOAA’s grid at Kennewick’s center; snow, wet days and snow on the ground from Ice Harbor Dam, WA. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 41° | 29° | 1.1" | 0.2" | 14 | 0 | 22° – 42° |
| February | 48° | 30° | 0.8" | 0.2" | 10 | 1 | 26° – 44° |
| March | 57° | 34° | 0.7" | 0.1" | 10 | 0 | 36° – 50° |
| April | 65° | 40° | 0.7" | 0.0" | 9 | 0 | 48° – 58° |
| May | 74° | 47° | 0.8" | 0.0" | 8 | 0 | 56° – 65° |
| June | 81° | 53° | 0.6" | 0.0" | 6 | 0 | 63° – 75° |
| July | 90° | 59° | 0.2" | 0.0" | 3 | 0 | 67° – 79° |
| August | 89° | 58° | 0.2" | 0.0" | 2 | 0 | 68° – 76° |
| September | 79° | 50° | 0.3" | 0.0" | 4 | 0 | 61° – 68° |
| October | 65° | 41° | 0.7" | 0.0" | 8 | 0 | 48° – 58° |
| November | 50° | 33° | 0.9" | 0.1" | 12 | 0 | 35° – 47° |
| December | 40° | 28° | 1.2" | 1.4" | 13 | 1 | 27° – 40° |
| Year | 65° | 42° | 8.2" | 2.0" | 97 | 2 |
How much a month can swing
A normal is an average. January swings the most: from 1991 to 2020 its average ranged from 22° to 42°. September is the most reliable, staying within 7°.
Where Kennewick’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 Kennewick’s center.
- Snow: Ice Harbor Dam, WA.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Kennewick, WA, 4 miles from the city’s center point, 150 ft lower; 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 Kennewick’s climate
What is the weather like in Kennewick?
A typical July afternoon reaches 90°, a January night drops to 29°, and about 2 inches of snow falls in a normal winter. Milder January nights than 71% of U.S. towns; hotter July afternoons than 77% of U.S. towns.
How cold does it get in Kennewick in winter?
December nights average 28°. About 76 nights a year reach 32° or below. In the coldest December of the last 30 years the month averaged 27°.
How much snow does Kennewick get?
About 2.0 inches in a normal winter at Ice Harbor Dam, WA, most of it in December, with snow on the ground about 2 days a year.
How hot does it get in Kennewick?
July, with a typical high of 90° and a low of 59°. About 48 days a year reach 90° and 8 reach 100° (Kennewick, WA).
When is the first and last frost in Kennewick?
In half of years the last spring frost (32°) comes by March 28 and the first fall frost by October 30, about 216 frost-free days, at Kennewick, WA.
What growing zone is Kennewick in?
Zone 7b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 6°.
What is the best time of year to visit Kennewick?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June, September and October. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Kennewick getting warmer?
Yes: 1991–2020 averaged 1.0° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 75% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Kennewick.
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.