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National Harbor, Maryland Weather

Cicadas claim the afternoon. Day 14 of summer. Read this microseason across nine climate regions →

National Harbor weather forecast — hour by hour, 7-day outlook, NOAA radar

National Harbor, MD
Saturday, July 4 at 7:03 PM
82
°
Overcast
Feels like
82°
Humidity
69%
Wind
20 mph
Sunrise
1:48 AM
Sunset
4:36 PM
National Harbor, MD
Hour by hour · 24h
24-Hour ForecastNational Harbor, MD: 24-hour forecast. Temperatures range from 75 to 99 degrees Fahrenheit with a 37% chance of precipitation at 7 PM.
L 75°H 99°
National Harbor, MD
7-day forecast
  1. Today
    Jul 4
    Light Drizzle
    37%
    0.01″
    103°81°—
  2. Sunday
    Jul 5
    Light Drizzle
    50%
    0.03″
    99°75°-4°
  3. Monday
    Jul 6
    Overcast
    80%
    —
    87°75°-12°
  4. Tuesday
    Jul 7
    Showers
    80%
    0.15″
    88°72°+1°
  5. Wednesday
    Jul 8
    Heavy Showers
    39%
    0.88″
    77°71°-11°
  6. Thursday
    Jul 9
    Partly Cloudy
    12%
    —
    93°68°+16°
  7. Friday
    Jul 10
    Drizzle
    41%
    0.06″
    96°73°+3°
National Harbor, MD
Next 24 hours · Warm now
HOT 90°70°88°105°6p12a6a12pnow 82°high 99°low 75°PRECIP %
National Harbor, MD
Anemometer · 24h winds · from true
NESW
From · True
S
183° · backing 48°
Direction
S
183°
Sustained
20
mph
Gust
39
mph
Peak 24h
39
avg 4
Beaufort · 5 · FRESH BRZ
0
CALM
<1
1
LIGHT AIR
1–3
2
LIGHT BRZ
4–7
3
GENTLE BRZ
8–12
4
MOD BRZ
13–18
5
FRESH BRZ
19–24
6
STRONG BRZ
25–31
7
NEAR GALE
32–38
24h · sust vs gust · mph
avg 4 · pk 39 @ 7:00p
010203040MPHB1B2B3B4B5B6B7B8-21h-18h-15h-12h-9h-6h-3h-24hNOWpk 394SUSTGUST
−24h−18h−12h−6hnow
Sustained 20 mph with gusts pulsing to 39 — flags snap, branches bend.
National Harbor, MD
Barometer · 24h pressure · mb
STORMRAINCHANGEFAIRDRY9901000101010201030
Pressure · mb
1012.3
+1.8 mb in 3h · rising · 29.89 inHg
Now
1012.3
mb
3h
+1.8
mb
12h
-0.9
mb
24h
0.0
mb
Regime · CHANGE
STORM
RAIN
CHANGE
FAIR
DRY
24h · Pressure · mb
range 1009–1014
9951000STORM|RAIN10051010RAIN|CHG1015CHG|FAIR10201025FAIR|DRY1030-21h-18h-15h-12h-9h-6h-3h-24hNOW1013.91009.11012.3
−24h−18h−12h−6hnow
Pressure climbing through the change line — drier air pushing in.
National Harbor, MD
Air quality
108
AQI
Unhealthy for Sensitive Groups
↑+53 in 6h

AQI 108 (Unhealthy for Sensitive Groups), driven by PM2.5. AQI up 53 in the last 6 hours — air quality is degrading. PM2.5 at 12.1 µg/m³, PM10 at 12.6 µg/m³ — typical background levels with no transport signature.

CAUTION Sensitive groups (children, elderly, respiratory conditions) should limit prolonged outdoor exertion.

PM 2.5DRIVERModerate
12.1μg/m³
PM 10Good
13μg/m³
NO₂Good
9μg/m³
OzoneUnhealthy SG
105μg/m³
UV IndexLow
0.4

What's driving it

Ozone × UV × Sky

Ozone at AQI 50. Overcast through the UV peak window (cloud cover ~100%) — afternoon ozone should stay flat.

Present
AQI 50
UV peak
0.3 at 1 PM
Sky at peak
overcast
Projected peak
AQI 6

PM × Wind × Precip

PM2.5 at 12.1 µg/m³, PM10 at 12.6 µg/m³ — typical background levels with no transport signature.

PM2.5/PM10
0.96
Wind
windy
Recent rain
1h in last 6h
Pattern
background

Trends

Seven days of AQI and PM2.5.

Hourly air-quality data from the Copernicus Atmosphere Monitoring Service, charted across the past and next several days. Dashed lines mark the AQI breakpoints at 50 (Good → Moderate) and 100 (Moderate → Unhealthy for Sensitive Groups).

7-DAY AQI TREND50100SATSUNMONTUEWEDTHUFRISAT7-DAY PM2.5 TREND · μg/m³400
National Harbor, MD
Sky cover · visibility · 24h
Cloud cover
100%
OVERCAST
100%0%−24h−18h−12h−6hnow
Visibility
45.7mi
UNLIMITED
132 mi0 mi−24h−18h−12h−6hnow
Earth · GOES-19 ABI
Full Disk · Visible · GeoColor
GOES-19 full disk Visible · GeoColor
True-color daytime, blue/IR sandwich at night
23:03 UTC · National Harbor, MD · NOAA NESDIS / STAR · up to 10848 px
Continental US · GOES-19 ABI
CONUS Sector · Visible · GeoColor
GOES-19 CONUS Visible · GeoColor
Daytime true-color, blue-light/IR sandwich at night
23:03 UTC · National Harbor, MD · NOAA NESDIS / STAR · 5-min cadence · up to 10000 px
National Harbor, MD
Satellite · infrared · animated
National Harbor, MD
Loading IR frames…
IR · cloud-top temp© RainViewer · Carto
National Harbor, MD
Almanac · Saturday, July 4
If the first of July be rainy weather, 'twill rain more or less for four weeks together.
Civil dawn
5:17 AM
Sunrise
1:48 AM
Daylight
14h 48m
Sunset
4:36 PM
Civil dusk
9:09 PM
Planting note
Harvest early potatoes. Begin drying onions on the surface.
National Harbor, MD
The moon
Waning Gibbous
78% illuminated
Moonrise
10:59 PM
Moonset
10:13 AM
In sign
♓︎ Pisces
National Harbor, MD
Microseason
Jul 1–5

Cicadas claim the afternoon

plant
Jan 151% of the yearDec 31

Read this microseason across nine climate regions →

National Harbor at a glance

  • Today vs. normal: 9°F above the seasonal normal for this latitude
  • Last frost: April 9 (climatological average for this latitude)
  • Microseason: Jul 1–5
  • Planting window: Harvest early potatoes. Begin drying onions on the surface.

16-Day Forecast — National Harbor

  1. Sat103°81°37%
  2. Sun99°75°50%
  3. Mon87°75°80%
  4. Tue88°72°80%
  5. Wed77°71°39%
  6. Thu93°68°12%
  7. Fri96°73°41%
  8. Sat94°69°40%
  9. Sun83°73°24%
  10. Mon82°69°19%
  11. Tue88°66°19%
  12. Wed95°72°33%
  13. Thu94°71°37%
  14. Fri93°74°42%
  15. Sat96°71°44%
  16. Sun92°71°46%

Forecast data from Open-Meteo (CC BY 4.0).

Right now in the garden

Peak growing season

As of July 4, the growing season is at its peak — frost is months away. Continue succession-planting beans and summer squash. Start fall brassicas (broccoli, cabbage, kale) from seed indoors for transplanting in late summer.

SPC Convective Outlook

Storm Prediction Center — National Harbor

SPC has placed National Harbor in the Enhanced Risk category for severe thunderstorms today.

  • TODAYENHEnhanced Risk
  • TOMORROWSLGTSlight Risk
  • DAY 3TSTMGeneral Thunderstorms

Numerous severe storms likely. Tornadoes, large hail, and damaging wind gusts possible across the area. Track NWS warnings if storms develop.

Source: NOAA / NWS Storm Prediction Center categorical convective outlook. Outlooks are re-issued multiple times per day; this page reflects the most recent SPC polygons covering the city’s coordinates.

January 1–5: The year turns in silence.January 6–10: Ice thickens on still water.January 11–15: Shortest shadows lengthen.January 16–20: Pheasants begin to call.January 21–25: Springs begin to thaw.January 26–31: Chickadees announce dawn.February 1–5: East wind softens the frost.February 6–10: Sap begins to rise.February 11–15: First snowdrops appear.February 16–20: Red-winged blackbirds return.February 21–25: Rain begins to replace snow.February 26–28: Skunk cabbage pushes through ice.March 1–5: Ice withdraws from the reservoir.March 6–10: Crocuses open to weak sun.March 11–15: Peepers call from the marsh.March 16–20: Woodcocks spiral at dusk.March 21–25: Equinox — light overtakes dark.March 26–31: Forsythia opens along the fences.April 1–5: Cherry blossoms drift like snow.April 6–10: Warblers appear in the understory.April 11–15: Magnolias bloom and fall in a day.April 16–20: Dogwoods float above the forest.April 21–25: Lilacs perfume the evening.April 26–30: Last frost releases the garden.May 1–5: Warblers flood the Ramble.May 6–10: Tulip poplars light their candles.May 11–15: Shad run up the rivers.May 16–20: Roses open along the stoops.May 21–25: Firefly scouts appear at dusk.May 26–31: Strawberries ripen in the sun.June 1–5: Fireflies rise from the lawn.June 6–10: Elderflowers open in hedgerows.June 11–15: Solstice approaches — longest light.June 16–20: Honeysuckle sweetens the night.June 21–25: Solstice — the sun stands still.June 26–30: Lightning bugs drift through oaks.July 1–5: Cicadas claim the afternoon.July 6–10: Queen Anne's lace lines the roads.July 11–15: Thunder builds each afternoon.July 16–20: Corn reaches for the tassels.July 21–25: Dog days settle in the haze.July 26–31: Katydids begin their chorus.August 1–5: Night falls a minute earlier.August 6–10: Sunflowers face the morning.August 11–15: Goldenrod begins to bloom.August 16–20: Crickets pulse through warm nights.August 21–25: First cool morning surprises.August 26–31: Monarchs stage for flight.September 1–5: School buses reappear.September 6–10: Asters purple the roadsides.September 11–15: Hawk migration over the Hudson.September 16–20: Equinox — dark overtakes light.September 21–25: Apples hang heavy on the branch.September 26–30: Geese begin to chevron south.October 1–5: Witch hazel blooms as others fade.October 6–10: Maples begin to blaze.October 11–15: Frost paints the garden black.October 16–20: Oaks turn bronze and russet.October 21–25: Leaves rattle down the gutters.October 26–31: Clocks fall back — dusk at five.November 1–5: Ginkgos drop overnight.November 6–10: Last leaves cling stubbornly.November 11–15: Juncos arrive from the north.November 16–20: Bare branches reveal the sky.November 21–25: First flurries dust the rooftops.November 26–30: Woodsmoke curls through the block.December 1–5: Darkness settles before dinner.December 6–10: Holly and winterberry persist.December 11–15: Shortest day approaches.December 16–20: Ice begins to form at the edges.December 21–25: Solstice — the sun begins return.December 26–31: The year turns in silence.🌱February 14 — First skunk-cabbage spathes thaw their way up☀️March 20 — Spring equinox — day and night balance🌸April 5 — Cherry blossoms peak in the parks🐦May 10 — Warbler migration peaks along the coast✨May 25 — First fireflies scout the meadows at dusk🌞June 21 — Summer solstice — longest day🦗July 25 — Peak cicada chorus in the afternoons🌊August 18 — Warmest sea-surface temperatures of the year🍂September 22 — Autumn equinox — the slow turn❄️October 25 — First widespread frost in the suburbs🍁November 10 — Peak leaf color across the Hudson Valley🌙December 21 — Winter solstice — longest night

Microseason · July 1–5

Cicadas claim the afternoon

Annual cicada buzz begins, peaking in the heat of the day.

Day 185 of 365 · Wedge 37 of 72

The solar year drawn as a wheel of 72 five-day windows. Each wedge is one microseason; the four colored arcs mark winter, spring, summer, and autumn; the small icons sit at notable phenological events. The crimson pointer creeps clockwise as the year turns.

Planting calendar

MonthPlantHarvest
January——
February——
March——
Aprillettuce, peas, spinach, radishes—
Maylettuce, peas, spinach, radishes, tomatoes, peppers, beans, squashlettuce, peas, radishes
Junetomatoes, peppers, beans, squashlettuce, peas, radishes
Julytomatoes, peppers, beans, squashtomatoes, beans, summer squash
August—tomatoes, beans, summer squash
Septemberfall brassicas, garlic (overwinter), carrotstomatoes, beans, summer squash
Octoberfall brassicas, garlic (overwinter), carrotswinter squash, tomatoes (last)
November——
December——

A year in weather

July is National Harbor's warmest stretch (~79°F) and January its coldest (~34°F); precipitation crests in August at 4.2 inches and ebbs in October to 2.6 inches.

MonthMean tempPrecipRainy days
January34°3.4″13
February37°2.8″12
March45°3.4″14
April56°3.6″16
May64°3.4″17
June73°3.8″17
July79°3.2″17
August78°4.2″18
September71°3.2″13
October60°2.6″11
November47°3.5″12
December38°3.8″13

Regional context

Per NOAA NCEI 1991-2020 normals, National Harbor runs from a 34°F January mean to 79°F in July, a 45°F seasonal spread, with near 41 inches of precipitation across about 174 wet days.

No season owns National Harbor's rain: August reaches 4.2 inches across 18.0 days and October keeps 2.6 inches on 11.4, an even spread through National Harbor's year. That lines National Harbor up with places like Forest Heights, MD, Oxon Hill, MD and Glassmanor, MD, fed by overlapping storm tracks.

National Harbor reaches its last hard frost near mid-April; that is the cue for peas, lettuce, spinach, and radishes. Heat-demanding starts go out a fortnight on in National Harbor, after the soil warms and cold snaps clear. The season ends by mid-November in National Harbor, once hard frosts set back in. A creek-bottom lot in National Harbor can lag National Harbor's last frost 7-10 days behind a south slope.

Similar climates: Forest Heights, MD, Oxon Hill, MD, Glassmanor, MD, Friendly, MD, Temple Hills, MD.

Frequently asked

When does it freeze in National Harbor?
National Harbor's last spring frost lands near mid-April, and in National Harbor the first fall frost follows around mid-November.
What is the rainy season in National Harbor?
August is the wettest month in National Harbor, about 4.2 inches on average; the year totals roughly 41 inches.
What is the warmest month in National Harbor?
On average July tops the year in National Harbor at about 79°F.
What is the coldest month in National Harbor?
The coldest stretch in National Harbor falls in January, around 34°F on average.
When can I start a vegetable garden in National Harbor?
Around mid-April, start frost-hardy crops in National Harbor; tomatoes and basil belong a fortnight later.
How many rainy days does National Harbor get?
National Harbor records around 174 days of measurable precipitation annually.
What hardiness zone is National Harbor?
Since January in National Harbor averages 34°F, National Harbor's USDA zone follows that floor — confirm it by ZIP.
What is the 10-day forecast for National Harbor?
National Harbor's extended outlook — daily high and low temperatures and precipitation chances for each upcoming day — is in the daily forecast above.
Will it rain this week in National Harbor?
See this week's day-by-day rain chances for National Harbor in the daily forecast above, and the next 24 hours in the hourly chart.
What is the weather like right now in National Harbor?
Current conditions for National Harbor and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
How often is the National Harbor forecast updated?
The National Harbor forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
When are sunrise and sunset in National Harbor?
Today's sunrise and sunset times for National Harbor are in the Almanac section above, along with civil dawn, civil dusk, and day length. Day length is longest near the summer solstice and shortest near the winter solstice.
How accurate is the weather forecast for National Harbor?
The next few days in National Harbor's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.

Climate

Set in a warm-summer humid continental zone, National Harbor, Maryland swings from 34°F in the heart of winter to 79°F at midsummer — a 45°F arc.

Across the year, National Harbor collects about 41 inches of precipitation over roughly 174 days with measurable rain or snow.

National Harbor sits at 38.8°N; that 45°F seasonal swing frames planting windows and frost dates across National Harbor.

All cities in Maryland →

Alexandria, VA weather →

ZIP codes in National Harbor

  • 20745

Climate normals from the Open-Meteo Climate API. Köppen approximation from NOAA NCEI U.S. Climate Regions. See methodology for data sources, editorial rules, and corrections. Maintainer: Brian Tighe.