Photo: ajay_suresh · CC BY 2.0Neither notably warm, cold, wet nor dry, Fairfax sits near the middle of U.S. towns
Nights in January average 26°. Expect the heaviest rain or snow in July and the lightest in February. Its January nights stay gentler than in 66% of U.S. towns. Garden planting can start around April 15; autumn frost returns near October 24.
A year in Fairfax at a glance
Each month’s typical high and low, and what it brings.
What stands out about Fairfax’s climate
Compared with towns across the U.S., with Fairfax’s place in Virginia beside it.
What a year in Fairfax feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 194 frost-free days a year
In half of years the last 32° night comes by April 15 and the first by October 24. Day counts come from NOAA’s station at Vienna, VA, 2.7 miles from the town’s center, at about the same height; frost dates and degree days from Washington Dc Dulles Airport, 11 miles away.
The 2023 USDA map puts Fairfax’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 21 inches of snow a winter
Snow, measured at Washington Dc Dulles Airport, is heaviest from January through February, about 7 inches a month. Precipitation (rain plus melted snow) adds up to 44 inches a year; July is the wettest month and February the driest. Rain or snow falls on about 121 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Fairfax
79% of the work is heating. Months averaging under 55° run from November through March.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Washington Dc Dulles Airport.
Living with Fairfax’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
194 frost-free days in zone 7b. The last frost comes by Apr 15 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 24.
Months with highs of 62–84° and lows of 40° or more: April, May, June, September and October. 8.4 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Fairfax from natural hazards, river flooding is the largest share (52%); heat waves, cold waves, winter storms and ice storms together are 10%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Fairfax and its neighbors
Every town next door is within a degree of Fairfax in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Fairfax’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 |
|---|---|---|---|---|
| Fairfax, VA | 26° | 87° | 44" | 21" |
| Fort Thomas, KY | 24° | 87° | 45" | 23" |
| Forestville, OH | 23° | 86° | 45" | 23" |
| Uniondale, NY | 25° | 85° | 46" | 19" |
| Fort Dix, NJ | 24° | 87° | 47" | 24" |
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 Fairfax averaged 1.7° warmer than the 1900s. The biggest change is in December (+2.8°).
A bigger shift than in 72% 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 Fairfax compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Fairfax’s place among Virginia’s.
Fairfax weather by month
Highs, lows and precipitation from NOAA’s grid at Fairfax’s center; snow, wet days and snow on the ground from Washington Dc Dulles Airport. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 43° | 26° | 3.0" | 6.9" | 10 | 4 | 26° – 41° |
| February | 46° | 28° | 2.6" | 7.0" | 9 | 5 | 26° – 44° |
| March | 55° | 34° | 3.6" | 3.9" | 11 | 2 | 38° – 54° |
| April | 66° | 44° | 3.4" | 0.1" | 11 | 0 | 51° – 61° |
| May | 74° | 54° | 4.2" | 0.0" | 13 | 0 | 59° – 70° |
| June | 83° | 63° | 4.2" | 0.0" | 11 | 0 | 68° – 77° |
| July | 87° | 68° | 4.4" | 0.0" | 11 | 0 | 72° – 80° |
| August | 85° | 66° | 3.6" | 0.0" | 9 | 0 | 70° – 79° |
| September | 78° | 59° | 4.2" | 0.0" | 9 | 0 | 65° – 73° |
| October | 67° | 47° | 3.7" | 0.0" | 8 | 0 | 53° – 64° |
| November | 56° | 37° | 3.1" | 0.3" | 9 | 0 | 41° – 52° |
| December | 47° | 30° | 3.5" | 2.8" | 10 | 2 | 29° – 49° |
| Year | 66° | 46° | 43.5" | 21.0" | 121 | 14 |
How much a month can swing
A normal is an average. December swings the most: from 1991 to 2020 its average ranged from 29° to 49°. September is the most reliable, staying within 7°.
Where Fairfax’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 Fairfax’s center.
- Snow: Washington Dc Dulles Airport.
- Frost dates, heating and cooling: Washington Dc Dulles Airport, 11 miles away.
- Freezing nights, 90° and 100° days: Vienna, VA, 2.7 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 Fairfax’s climate
What is the weather like in Fairfax?
A typical July afternoon reaches 87°, a January night drops to 26°, and about 21 inches of snow falls in a normal winter. Milder January nights than 66% of U.S. towns; hotter July afternoons than 60% of U.S. towns.
How cold does it get in Fairfax in winter?
January nights average 26°. About 99 nights a year reach 32° or below. In the coldest January of the last 30 years the month averaged 26°.
How much snow does Fairfax get?
About 21 inches in a normal winter at Washington Dc Dulles Airport, heaviest from January through February, about 7 inches a month, with snow on the ground about 14 days a year.
How hot does it get in Fairfax?
July, with a typical high of 87° and a low of 68°. About 13 days a year reach 90° (Washington Dc Dulles Airport).
When is the first and last frost in Fairfax?
In half of years the last spring frost (32°) comes by April 15 and the first fall frost by October 24, about 194 frost-free days, at Washington Dc Dulles Airport.
What growing zone is Fairfax 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 Fairfax?
By one simple rule (highs of 62–84° and lows of 40° or more), April, May, June, September and October. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Fairfax getting warmer?
Yes: 1991–2020 averaged 1.7° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 72% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Fairfax.
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.