Ashburn weather in May

In May, Ashburn sees average daytime highs of 74°F and overnight lows near 56°F, with 3.8 in of rain across 11.3 wet days and about 14.1 hours of daylight. It is the 5th-warmest and 3rd-wettest month of the year here.

Highs climb over the month, from about 71°F in the first days to 78°F by the end. The sky is clear or mostly clear about 25% of the time in May, and the air most often feels dry.

Daylight stretches from about 13 h 36 min at the start of May to 14 h 30 min by month's end. Set against the rest of the year, May is Ashburn's 12th-clearest and 8th-windiest month. For the whole year in context, see Ashburn's year-round climate.

Daytime high
74°
5th warmest
Overnight low
56°
8th coldest
Rainfall
3.8 in
11.3 wet days
Daylight
14 h 06 min
5:02 AM – 7:10 PM
Cloud cover
63%
12th clearest
Wind
6 mph
8th windiest
Solar energy
5.68 kWh/m²
Travel score
6.5
out of 10

Ashburn is census-designated place in Loudoun County, Virginia, United States.

Density
972/km²
people per km²
Founded
1802

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 71°F in the first days to 78°F by the end.

A typical May day in Ashburn reaches about 74°F in the afternoon and slips back to 56°F overnight — a 19°F spread between the day's warmth and the night's chill. On most days the high lands between 62°F and 86°F. Set against its neighbours, May runs about 9°F warmer than April and about 9°F cooler than June.

40°60°80°151015202531
Avg high (°F)Avg low (°F)
17051
27051
37152
47152
57152
67153
77253
87253
97253
107254
117354
127354
137355
147355
157455
167455
177456
187456
197556
207557
217657
227657
237658
247758
257759
267759
277859
287860
297860
307960
317961

How May really feels in Ashburn

Once humidity and wind are folded in, May averages 0 days that feel above 90°F and 0 that feel at or below 32°F — the comfort signal a plain temperature reading hides.

Days feeling ≥ 90°F
0
heat index over the day's high
Days feeling ≤ 32°F
0
wind chill below the day's low

May sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Ashburn weather by month

How May compares with the rest of the year at a glance. May is the 5th-warmest and 3rd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan42° / 28°3.08.639.60.3
Feb45° / 29°2.88.1310.51.1
Mar54° / 36°3.810211.73.3
Apr66° / 46°3.410.30.1135.8
May74° / 56°3.811.3014.16.5
Jun83° / 65°3.411.2014.75.5
Jul88° / 69°3.911.8014.54.4
Aug85° / 68°3.310.4013.55.1
Sep78° / 60°4.49.5012.36.7
Oct67° / 49°3.47.80116.5
Nov55° / 38°3.07.60.39.93.9
Dec46° / 32°3.59.12.19.31.3

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 25% of the time in May, the cloudiest month of the year.

Beyond those clear spells, partly cloudy skies cover about 17% of May, with mostly cloudy or overcast conditions the remaining 58%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14357
24357
34357
44456
54456
64456
74456
84456
94357
104357
114357
124258
134258
144258
154159
164159
174159
184060
193862
203862
213862
223862
234060
244060
254060
264159
274159
284258
294258
304357
314258

Chance of precipitation in May

Any precipitation

Ashburn gets around 3.8 in of rain over 11.3 wet days in May. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 36% and peaks near 39% on the wettest days.

0%10%20%30%40%50%151015202531
Rain chance (%)
139
238
338
438
538
637
737
837
937
1037
1137
1237
1337
1436
1536
1636
1735
1835
1935
2035
2136
2236
2335
2435
2535
2635
2735
2835
2935
3035
3135

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

Most of May feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, May lands in the dry band about 58% of days. Sticky, muggy-or-worse air turns up on roughly 8% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
17615810
27515910
373161010
472171010
570181110
669181210
769181210
866191320
966191320
1064191430
1164191430
1263191440
1362191540
1461191550
1561191550
1660181660
1759181670
1858181770
1957181780
2055181890
21521819101
22501919111
23491920121
24481920121
25461921131
26451921141
27432021141
28422022151
29412122161
30392122161
31382122171

Wind in May

Winds average 6 mph in May.

Across May, daily wind ranges from about 6 mph on the calmest days to 7 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)Feels
17calm
27calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm
316calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 13 h 36 min at the start of May to 14 h 30 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 54 minutes over May. Sunrise moves from 5:19 AM to 4:52 AM, and sunset from 6:56 PM to 7:23 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.65:196:56
213.75:176:57
313.75:166:58
413.75:156:59
513.85:147:00
613.85:137:00
713.85:127:01
813.95:107:02
913.95:097:03
1013.95:087:04
1114.05:077:05
1214.05:067:06
1314.05:057:07
1414.15:047:08
1514.15:037:09
1614.15:027:10
1714.25:017:11
1814.25:017:12
1914.25:007:13
2014.24:597:14
2114.34:587:15
2214.34:577:15
2314.34:577:16
2414.44:567:17
2514.44:557:18
2614.44:557:19
2714.44:547:20
2814.44:547:20
2914.54:537:21
3014.54:527:22
3114.54:527:23

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.68 kWh/m².

For context, solar energy here swings from a low near 1.95 kWh/m² to a high of 6.15 kWh/m² in June across the year — May's 5.68 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.5Bright
25.5Bright
35.5Bright
45.5Bright
55.5Bright
65.5Bright
75.5Bright
85.5Bright
95.5Bright
105.6Bright
115.6Bright
125.6Bright
135.6Bright
145.6Bright
155.6Bright
165.6Bright
175.6Bright
185.7Bright
195.7Bright
205.7Bright
215.7Bright
225.7Bright
235.8Bright
245.8Bright
255.8Bright
265.8Bright
275.8Bright
285.9Bright
295.9Bright
305.9Bright
315.9Bright
Planning a trip in May

Is May a good time to visit Ashburn?

Our two travel scores rate May for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

6.5
Sightseeing
2nd-best month of the year
5.2
Beach & pool
5th-best month of the year

May is a reasonable time to visit Ashburn for sightseeing.

What to pack for Ashburn in May

From May's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In May, Ashburn sees daytime highs around 74°F and nights near 56°F. Worth packing: light clothes, rain gear and sun protection. About 11 days see rain.

light clothesrain gearsun protection

UV index in Ashburn in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 8 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Ashburn peaks around July 10 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 19 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 9 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateLowJul 10UV 9Dec 19UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5High
Apr6High
May8Very high
Jun9Very high
Jul9Very high
Aug7High
Sep6High
Oct4Moderate
Nov3Moderate
Dec2Low

Air quality in Ashburn in May

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where May falls, not just the annual average.

Air quality in Ashburn is worst in July — around 17 µg/m³ PM2.5 (moderate), about 1.9× the cleanest month (November, 9 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1317 µg/m³Nov 129 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb12Moderate
Mar13Moderate
Apr13Moderate
May15Moderate
Jun16Moderate
Jul17Moderate
Aug15Moderate
Sep12Moderate
Oct9Good
Nov9Good
Dec10Good
Location & terrain

Where is Ashburn?

Ashburn sits at 39.0°N, 77.5°W, 295 ft above sea level, in United States. The nearest listed city is Sterling, 4.3 mi away.

Topography around Ashburn

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Ashburn.

Within 2 miles, the terrain around Ashburn has only modest variations in elevation — a maximum elevation change of 299 ft around an average of 299 ft above sea level; within 10 miles, significant variations in elevation — a maximum elevation change of 840 ft; within 50 miles, large variations in elevation — a maximum elevation change of 3,609 ft.

The land around Ashburn is covered by trees (54%) and artificial surfaces (27%) within 2 miles, trees (56%) and grassland (22%) within 10 miles, and trees (65%) and grassland (20%) within 50 miles.

2 miles
299 ft
10 miles
840 ft
50 miles
3,609 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
May weather nearby: Sterling 4.3 mi · Leesburg 6.2 mi · Herndon 7.5 mi · South Riding 8.7 mi · Oak Hill 9.3 mi · Reston 9.3 mi · Chantilly 11 mi · Great Falls 11 mi

United States travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 100% of US
price level, 2025
GDP per capita
$90,027
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
5.8
per 100k, 2023
Road deaths
12.7
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Ashburn (39.0437°, -77.4875°, elevation 295 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).