Manassas, Virginia climate: Normal weather by month, frost dates and records
Manassas's normal year runs from 24°F January nights to 88°F July afternoons. (NOAA 1991-2020 normals)
In metric: a yearly mean of 13.1°C, January lows of −4°C, July highs of 31°C.
- NOAA stationManassas
- Station IDUSC00445204
- Location38.73°N 77.49°W
- Elevation245 ft (75 m)
- From the center1 miles
- Population43,616
On October 22, the normal high in Manassas is 65°F and the normal low 43°F.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Manassas.
- Jan 42° 24°
- Feb 46° 26°
- Mar 54° 32°
- Apr 66° 43°
- May 74° 54°
- Jun 83° 64°
- Jul 88° 69°
- Aug 85° 67°
- Sep 78° 58°
- Oct 67° 46°
- Nov 56° 35°
- Dec 47° 29°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Manassas each month?
July is the warmest month, with normal highs of 88°F; January the coldest, with normal lows of 24°F.
| Month | High | Low | Mean | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|
| January | 42°F | 24°F | 33.3°F | – | <1 | 24 | 9 h 40 min |
| February | 46°F | 26°F | 35.7°F | – | <1 | 21 | 10 h 40 min |
| March | 54°F | 32°F | 43.1°F | – | <1 | 15 | 11 h 50 min |
| April | 66°F | 43°F | 54.5°F | – | <1 | 2 | 13 h 10 min |
| May | 74°F | 54°F | 63.9°F | – | 2 | <1 | 14 h 20 min |
| June | 83°F | 64°F | 73.3°F | – | 7 | <1 | 14 h 50 min |
| July | 88°F | 69°F | 78.1°F | – | 17 | <1 | 14 h 40 min |
| August | 85°F | 67°F | 76.0°F | – | 11 | <1 | 13 h 40 min |
| September | 78°F | 58°F | 68.3°F | – | 3 | <1 | 12 h 30 min |
| October | 67°F | 46°F | 56.3°F | – | <1 | 2 | 11 h 20 min |
| November | 56°F | 35°F | 45.9°F | – | <1 | 12 | 10 h 10 min |
| December | 47°F | 29°F | 37.6°F | – | <1 | 20 | 9 h 30 min |
| Year (annual) | 66°F | 46°F | 55.5°F | – | 41 | 94 |
The same normals in °C and millimetres
| Month | High | Low | Mean |
|---|---|---|---|
| January | 6°C | −4°C | 0.7°C |
| February | 8°C | −3°C | 2.1°C |
| March | 12°C | 0°C | 6.2°C |
| April | 19°C | 6°C | 12.5°C |
| May | 23°C | 12°C | 17.7°C |
| June | 28°C | 18°C | 22.9°C |
| July | 31°C | 20°C | 25.6°C |
| August | 30°C | 19°C | 24.4°C |
| September | 26°C | 15°C | 20.2°C |
| October | 19°C | 8°C | 13.5°C |
| November | 14°C | 2°C | 7.7°C |
| December | 8°C | −2°C | 3.1°C |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Sterling (14 miles away), gets 21 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00445204; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Manassas?
Normal highs sit between 65°F and 85°F in April, May, June, September and October.
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00445204.
When is the last frost in Manassas?
In Manassas, the last spring frost (32°F) comes after April 12 in half of years and after April 24 in one year in ten; the first autumn frost comes before October 27 in half of years and before October 13 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- April 121 year in 10 after April 24; 9 in 10 after March 30
- First autumn frost, half of years before
- October 271 year in 10 before October 13; 9 in 10 before November 7
NOAA puts the median frost-free season at 197 days, and the season without a hard freeze (28°F) at 218 days.
A hard freeze (28°F) comes after April 1 in half of springs and before November 5 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Manassas in zone 7a in ZIP code 20110.
Frost dates for every NOAA station in Virginia · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00445204; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get in Manassas?
In a normal year in Manassas, 41 days a year reach 90°F (2 of them 100°F or more) and 94 nights fall to 32°F or colder.
- Days at 90°F or more
- 41a normal year
- Days at 100°F or more
- 2a normal year
- Nights at 32°F or colder
- 94a normal year
- Days that stay below freezing
- 10high of 32°F or less
Source: NOAA NCEI 1991-2020 annual normals, station USC00445204.
How sunny is Manassas?
Over a year 75% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Manassas, 4.1 kWh per square metre a day. July is the sunniest month (80%) and January the cloudiest (70%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 70% | 2.2 |
| February | 70% | 3.0 |
| March | 71% | 4.0 |
| April | 72% | 5.0 |
| May | 73% | 5.6 |
| June | 79% | 6.2 |
| July | 80% | 6.0 |
| August | 79% | 5.4 |
| September | 76% | 4.4 |
| October | 74% | 3.3 |
| November | 75% | 2.5 |
| December | 70% | 1.9 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Manassas need?
A normal year in Manassas brings 4,707 heating degree days, 12% fewer than the median U.S. place (5,373), and 1,270 cooling degree days, 40% more than the median (908). Six months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 3,908 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 982 | 0 |
| February | 822 | 0 |
| March | 680 | 1 |
| April | 335 | 19 |
| May | 117 | 83 |
| June | 10 | 257 |
| July | 0 | 404 |
| August | 1 | 340 |
| September | 46 | 143 |
| October | 291 | 21 |
| November | 575 | 1 |
| December | 849 | 0 |
| Year (annual) | 4,707 | 1,270 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00445204. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
How does Manassas's climate compare?
Manassas is warmer than 36 of the other 80 places with their own NOAA record in Virginia. Across the 7,247 U.S. stations with normals, its annual mean of 55.5°F is warmer than 62%.
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers.
Which places near Manassas share this climate record?
16 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Dale City, VAalso near: Quantico (11 mi, 58.1°F a year); Vienna (17 mi, 54.0°F a year)72,793 people · 10 mi SE
- Linton Hall, VA42,077 people · 5 mi W
- Buckhall, VA20,447 people · 3 mi SE
- Sudley, VA18,420 people · 4 mi N
- Gainesville, VA18,036 people · 9 mi NW
- Bull Run, VA16,688 people · 4 mi NW
- Manassas Park, VA16,611 people · 4 mi NE
- Yorkshire, VA10,678 people · 4 mi NE
- Independent Hill, VA10,217 people · 7 mi SE
- Loch Lomond, VA4,460 people · 3 mi N
- Union Mill, VA4,351 people · 7 mi NE
- County Center, VA4,233 people · 8 mi E
- Haymarket, VA1,594 people · 9 mi NW
- Nokesville, VA1,179 people · 5 mi SW
- Innovation, VA1,139 people · 2 mi NW
- Clifton, VA242 people · 7 mi NE
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Manassas's climate
What is the coldest month in Manassas?
January, with a normal high of 42°F and a normal low of 24°F. The warmest is July (88°F by day, 69°F at night).
Does it snow in Manassas?
Yes. NOAA publishes no 1991-2020 snowfall normal for Manassas's NOAA station; the nearest record that keeps one, Sterling (14 miles away), records 21 inches of snow in a normal year.
What plant hardiness zone is Manassas in?
The USDA's 2023 map puts Manassas in zone 7a in ZIP code 20110.
How late can frost come in Manassas?
In half of years the last 32°F night comes after April 12; in one year in ten it comes after April 24. Waiting until April 24 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Virginia climateThe statewide normals and every place in the state
- Sterling, VA14 miles from this station, 55.7°F a year
- Warrenton, VA16 miles from this station, 54.9°F a year
- Vienna, VA16 miles from this station, 54.0°F a year
- Weather Office Sterling, VA17 miles from this station, 55.4°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made