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William Gunnell HouseWilliam Gunnell House · Photo: JERRYE & ROY KLOTZ MD · CC BY-SA 3.0
Climate in Great Falls · NOAA 1991–2020 normals

No extremes in Great Falls: its weather tracks the middle of U.S. towns

The warmest part of a July day comes in at 87° on average. Winters are mild: January nights here are milder than in 65% of U.S. towns. The latest 30-year average runs 1.7° warmer than 1901–2000’s, with December up the most. Warm coats and heating bills mark the months from November to March, when means dip under 50°.

Milder January nights than 65% of U.S. towns#141Mildest winters  of 225 in VA
Less snow than 51% of U.S. towns#166Least snow  of 225 in VA
All VA rankings →

A year in Great Falls at a glance

Each month’s typical high and low, and what it brings.

Jan42°26° 7" snow
Feb46°27° 7" snow
Mar54°34° 4" snow
Apr66°44° Last frost ~Apr 15
May74°53° 1 day 90°+Wettest
Jun83°62° 6 days 90°+
Jul87°67° 13 days 90°+
Aug85°65° 9 days 90°+
Sep78°58° 3 days 90°+
Oct67°46° First frost ~Oct 24
Nov now56°36°
Dec46°30°

What stands out about Great Falls’ climate

Compared with towns across the U.S., with Great Falls’ place in Virginia beside it.

A normal year

What a year in Great Falls feels like

Typical highs and lows by season and by month, from NOAA’s 30-year normals.

Winter
45° / 27°
5 days with 1"+ of snow
Spring
65° / 44°
Last frost around Apr 15
Summer
85° / 65°
33 days reach 90°
Fall
67° / 47°
First frost around Oct 24
Best months to be outsideAprMayJunSepOctHighs of 62–84° and lows of 40° or more
Frost, heat & the growing season

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. Frost and day counts come from NOAA’s station at Washington Dc Dulles Airport, 10 miles from the town’s center, at about the same height.

102
nights at or below 32° in a normal year
148th fewest of 225 in Virginia
Fewer freezing nights than 59% of U.S. towns
<1
nights at or below 0°
143rd fewest of 225 in Virginia
Fewer nights at or below 0° than 61% of U.S. towns
33
days that reach 90°
77th most of 225 in Virginia
More 90° days than 65% of U.S. towns
<1
days that reach 100°
93rd most of 225 in Virginia
More 100° days than 65% of U.S. towns
7bUSDA zone
Plant hardiness zone 7b

The 2023 USDA map puts Great Falls’ 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°

24
JFMAMJJASOND

90° days by month

Average days at 90° or more

13
JFMAMJJASOND
Rain & snow

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; May is the wettest month and February the driest. Rain or snow falls on about 121 days a year.

44"
Rain + melted snow a year
114th wettest of 225 in Virginia
Wetter than 54% of U.S. towns
21"
Snow in a normal winter
166th least snowy of 225 in Virginia
Less snow than 51% of U.S. towns
14 days
With 1"+ of snow on the ground
123rd fewest of 205 in Virginia
Fewer days with snow on the ground than 58% of U.S. towns

Rain + melted snow by month

Inches of water

4.3"
JFMAMJJASOND

Snowfall by month

Inches of snow

7"
JFMAMJJASOND
Heating & cooling

Heating and cooling a home in Great Falls

79% of the work is heating. Months averaging under 55° run from November through April.

4,604 heating degree daysLess heating than 64% of U.S. towns
1,233 cooling degree daysMore cooling than 65% of U.S. towns

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 here

Living with Great Falls’ climate

What the numbers mean for a garden, a free afternoon and a bad-weather day.

The garden window

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.

Get outside

Months with highs of 62–84° and lows of 40° or more: April, May, June, September and October. 47 miles of trails are waiting.

Parks & trails →
Storms and extremes

Of the yearly building losses FEMA expects in Great Falls from natural hazards, river flooding is the largest share (77%); heat waves, cold waves, winter storms and ice storms together are 6%. Normals are averages; the hazards page covers the extremes.

Natural hazards →
Next door

Great Falls and its neighbors

Every town next door is within a degree of Great Falls in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.

Brookmont: January low 26°, July high 87°Cabin John: January low 26°, July high 88°Pimmit Hills: January low 26°, July high 87°Tysons: January low 26°, July high 87°Idylwood: January low 26°, July high 87°Arlington: January low 26°, July high 88°Falls Church: January low 26°, July high 87°Rockville: January low 25°, July high 86°North Potomac: January low 25°, July high 86°North Bethesda: January low 26°, July high 87°Bethesda: January low 26°, July high 87°Germantown: January low 25°, July high 86°Lowes Island: January low 25°, July high 87°Gaithersburg: January low 25°, July high 86°Reston: January low 26°, July high 87°Vienna: January low 26°, July high 87°Oakton: January low 26°, July high 87°Difficult Run: January low 26°, July high 87°Herndon: January low 26°, July high 87°McLean: January low 26°, July high 87°Travilah: January low 26°, July high 87°Potomac: January low 26°, July high 87°Darnestown: January low 25°, July high 87°Great Falls Crossing: January low 26°, July high 87°Wolf Trap: January low 26°, July high 87°Dranesville: January low 26°, July high 87°Great Falls: January low 26°, July high 87°Great FallsMcLeanTravilahPotomacDarnestownGreat Falls CrossingWolf TrapDranesville
ColderMilder25° to 26°
Darnestown25.4° about the same
Great Falls25.6°
Travilah25.6° about the same
Dranesville25.6° about the same
Potomac25.7° about the same
Great Falls Crossing25.7° about the same
Wolf Trap25.9° about the same
McLean26.1° about the same

Climates most like Great Falls’, 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.

TownJan. lowJuly highPrecip.Snow
Great Falls, VA26°87°44"21"
Fort Thomas, KY24°87°45"23"
Forestville, OH23°86°45"23"
Fort Dix, NJ24°87°47"24"
Levittown, PA24°87°47"27"

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.

Then and now

Warmer than it used to be

The last 30 years in Great Falls averaged 1.7° warmer than the 1900s. The biggest change is in December (+2.9°).

+1.7°1991–2020 vs. 1901–2000

A bigger shift than in 75% of U.S. towns.

Winter+2.3°now 36°, was 34°
Spring+1.5°now 54°, was 53°
Summer+1.7°now 75°, was 73°
Fall+1.4°now 57°, was 56°

Change by month

JanFebMarAprMayJunJulAugSepOctNovDec

The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.

Compared with other towns

How Great Falls compares

Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Great Falls’ place among Virginia’s.

Summer heat87° July high
Hotter July afternoons than 62% of U.S. towns153rd hottest of 225 in Virginia
Winter cold26° January low
Milder January nights than 65% of U.S. towns141st mildest of 225 in Virginia
Precipitation44" a year
Wetter than 54% of U.S. towns114th wettest of 225 in Virginia
Snow21" a winter
Less snow than 51% of U.S. towns166th least snowy of 225 in Virginia
Hot days33 days at 90°+
More 90° days than 65% of U.S. towns77th most of 225 in Virginia
Freezing nights102 a year
Fewer freezing nights than 59% of U.S. towns148th fewest of 225 in Virginia
Growing season194 frost-free days
A longer frost-free season than 62% of U.S. towns151st longest of 225 in Virginia
Month by month

Great Falls weather by month

Highs, lows and precipitation from NOAA’s grid at Great Falls’ center; snow, wet days and snow on the ground from Washington Dc Dulles Airport. 1991–2020 normals.

MonthHighLowRain + meltSnowWet daysSnow on ground30-yr range
January42°26°3.0"6.9"10426° – 41°
February46°27°2.6"7.0"9526° – 44°
March54°34°3.7"3.9"11238° – 54°
April66°44°3.4"0.1"11051° – 60°
May74°53°4.3"0.0"13059° – 70°
June83°62°4.3"0.0"11068° – 77°
July87°67°4.3"0.0"11072° – 80°
August85°65°3.5"0.0"9070° – 79°
September78°58°4.2"0.0"9065° – 72°
October67°46°3.7"0.0"8053° – 63°
November56°36°3.1"0.3"9040° – 52°
December46°30°3.5"2.8"10229° – 49°
Year65°46°43.7"21.0"12114
Year to year

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°.

Coldest to warmest month in 30 yearsNormal
Sources

Where Great Falls’ 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 Great Falls’ center.
  • Snow: Washington Dc Dulles Airport.
  • Frost, freezing nights, 90° and 100° days, heating and cooling: Washington Dc Dulles Airport, 10 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 Great Falls’ climate

What is the weather like in Great Falls?

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 65% of U.S. towns; hotter July afternoons than 62% of U.S. towns.

How cold does it get in Great Falls in winter?

January nights average 26°. About 102 nights a year reach 32° or below. In the coldest January of the last 30 years the month averaged 26°.

How much snow does Great Falls 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 Great Falls?

July, with a typical high of 87° and a low of 67°. About 33 days a year reach 90° (Washington Dc Dulles Airport).

When is the first and last frost in Great Falls?

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 Great Falls 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 Great Falls?

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 Great Falls getting warmer?

Yes: 1991–2020 averaged 1.7° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 75% of U.S. towns.

Neighbors talk weather

Gardens, snow, and the best days of the year in Great Falls.

Town Square →
Ask your neighbors

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.