Weather StoryAlmanac, microseasons, and the day's weather story.

Chillum, Maryland Weather

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

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

Chillum, MD
Saturday, July 4 at 5:53 PM
102
°
Mostly Clear
Feels like
105°
Humidity
30%
Wind
6 mph
Sunrise
1:47 AM
Sunset
4:36 PM
Chillum, MD
Hour by hour · 24h
24-Hour ForecastChillum, MD: 24-hour forecast. Temperatures range from 74 to 102 degrees Fahrenheit with a 31% chance of precipitation at 2 AM.
L 74°H 102°
Chillum, MD
7-day forecast
  1. Today
    Jul 4
    Drizzle
    22%
    0.03″
    102°78°—
  2. Sunday
    Jul 5
    Heavy Rain
    54%
    1.6″
    98°74°-4°
  3. Monday
    Jul 6
    Light Drizzle
    82%
    —
    86°75°-12°
  4. Tuesday
    Jul 7
    Thunderstorm
    82%
    0.29″
    90°72°+4°
  5. Wednesday
    Jul 8
    Light Rain
    38%
    0.20″
    78°70°-12°
  6. Thursday
    Jul 9
    Overcast
    12%
    —
    93°69°+15°
  7. Friday
    Jul 10
    Drizzle
    42%
    0.06″
    93°73°0°
Chillum, MD
Next 24 hours · Hot now
HOT 90°65°88°110°6p12a6a12pnow 102°high 102°low 74°PRECIP %
Chillum, MD
Anemometer · 24h winds · from true
NESW
From · True
SSW
208° · backing 62°
Direction
SSW
208°
Sustained
6
mph
Gust
9
mph
Peak 24h
13
avg 4
Beaufort · 2 · LIGHT 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 13 @ 9:00p
010203040MPHB1B2B3B4B5B6B7B8-21h-18h-15h-12h-9h-6h-3h-24hNOWpk 344SUSTGUST
−24h−18h−12h−6hnow
A whisper of wind — leaves barely shift on the trees.
Chillum, MD
Barometer · 24h pressure · mb
STORMRAINCHANGEFAIRDRY9901000101010201030
Pressure · mb
1009.6
-2.1 mb in 3h · falling rapidly · 29.81 inHg
Now
1009.6
mb
3h
-2.1
mb
12h
-2.6
mb
24h
-2.5
mb
Regime · RAIN
STORM
RAIN
CHANGE
FAIR
DRY
24h · Pressure · mb
range 1010–1014
9951000STORM|RAIN10051010RAIN|CHG1015CHG|FAIR10201025FAIR|DRY1030-21h-18h-15h-12h-9h-6h-3h-24hNOW1013.51009.71009.7
−24h−18h−12h−6hnow
Pressure giving way — clouds thicken and rain edges closer.
Chillum, MD
Air quality
123
AQI
Unhealthy for Sensitive Groups
↑+68 in 6h

AQI 123 (Unhealthy for Sensitive Groups), driven by Ozone. AQI up 68 in the last 6 hours — air quality is degrading. Ozone at AQI 108 — peak already passed at 1 PM under clear skies. Levels should ease through evening.

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

PM 2.5Good
9.2μg/m³
PM 10Good
10μg/m³
NO₂Good
2μg/m³
OzoneDRIVERUnhealthy
143μg/m³
UV IndexModerate
2.4

What's driving it

Ozone × UV × Sky

Ozone at AQI 108 — peak already passed at 1 PM under clear skies. Levels should ease through evening.

Present
AQI 108
UV peak
2.0 at earlier today
Sky at peak
clear
Projected peak
AQI 108

PM × Wind × Precip

PM2.5 at 9.2 µg/m³, PM10 at 10.2 µg/m³ — typical background levels with no transport signature.

PM2.5/PM10
0.90
Wind
light
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/m³330
Chillum, MD
Sky cover · visibility · 24h
Cloud cover
27%
MOSTLY CLEAR
100%0%−24h−18h−12h−6hnow
Visibility
119.9mi
UNLIMITED
115 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
21:53 UTC · Chillum, 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
21:53 UTC · Chillum, MD · NOAA NESDIS / STAR · 5-min cadence · up to 10000 px
Chillum, MD
Satellite · infrared · animated
Chillum, MD
Loading IR frames…
IR · cloud-top temp© RainViewer · Carto
Chillum, MD
Almanac · Saturday, July 4
If the first of July be rainy weather, 'twill rain more or less for four weeks together.
Civil dawn
5:16 AM
Sunrise
1:47 AM
Daylight
14h 49m
Sunset
4:36 PM
Civil dusk
9:10 PM
Planting note
Harvest early potatoes. Begin drying onions on the surface.
Chillum, MD
The moon
Waning Gibbous
78% illuminated
Moonrise
10:59 PM
Moonset
10:12 AM
In sign
♓︎ Pisces
Chillum, MD
Microseason
Jul 1–5

Cicadas claim the afternoon

plant
Jan 151% of the yearDec 31

Read this microseason across nine climate regions →

Chillum at a glance

  • Today vs. normal: 29°F above the seasonal normal for this latitude
  • Last frost: April 10 (climatological average for this latitude)
  • Microseason: Jul 1–5
  • Planting window: Harvest early potatoes. Begin drying onions on the surface.

16-Day Forecast — Chillum

  1. Sat102°78°22%
  2. Sun98°74°54%
  3. Mon86°75°82%
  4. Tue90°72°82%
  5. Wed78°70°38%
  6. Thu93°69°12%
  7. Fri93°73°42%
  8. Sat93°70°38%
  9. Sun83°72°22%
  10. Mon82°70°20%
  11. Tue88°67°18%
  12. Wed95°71°33%
  13. Thu95°72°37%
  14. Fri92°77°42%
  15. Sat95°73°44%
  16. Sun91°72°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 — Chillum

SPC has placed Chillum 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

In Chillum, July runs warmest near 78°F and January coldest around 32°F, while August is the wettest month (4.2 inches) and October the driest (2.6 inches).

MonthMean tempPrecipRainy days
January32°3.3″13
February35°2.8″12
March44°3.4″15
April55°3.7″17
May63°3.5″18
June72°3.9″17
July78°3.2″17
August77°4.2″18
September70°3.4″14
October59°2.6″11
November46°3.6″12
December37°3.9″14

Regional context

Chillum swings from 32°F in January to 78°F in July (46°F) per NOAA NCEI 1991-2020 normals; precipitation in Chillum runs about 41.5 inches on roughly 175 measurable days.

Chillum's precipitation spreads evenly: August peaks at 4.2 inches on 17.8 wet days, while October holds 2.6 inches over 11.1 — no month dominates Chillum's rain calendar. It is a balanced pattern Chillum shares with places like Hyattsville, MD, Langley Park, MD and Takoma Park, MD.

Chillum 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 Chillum, after the soil warms and cold snaps clear. By mid-November, frost is back in Chillum — protect or harvest anything tender. A creek-bottom lot in Chillum can lag Chillum's last frost 7-10 days behind a south slope.

Similar climates: Hyattsville, MD, Langley Park, MD, Takoma Park, MD, Mount Rainier, MD, University Park, MD.

Frequently asked

When does it freeze in Chillum?
Frost typically leaves Chillum by mid-April and returns to Chillum near mid-November.
What is the rainy season in Chillum?
Rainfall in Chillum peaks in August near 4.2 inches, out of about 42 inches annually.
What is the warmest month in Chillum?
On average July tops the year in Chillum at about 78°F.
What is the coldest month in Chillum?
The coldest stretch in Chillum falls in January, around 32°F on average.
When can I start a vegetable garden in Chillum?
Around mid-April, start frost-hardy crops in Chillum; tomatoes and basil belong a fortnight later.
How many rainy days does Chillum get?
Expect roughly 175 wet days a year in Chillum.
What hardiness zone is Chillum?
Because Chillum bottoms near 32°F in January, that winter low sets Chillum's USDA zone — verify by ZIP.
What is the 10-day forecast for Chillum?
Chillum'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 Chillum?
See this week's day-by-day rain chances for Chillum in the daily forecast above, and the next 24 hours in the hourly chart.
What is the weather like right now in Chillum?
Current conditions for Chillum and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
How often is the Chillum forecast updated?
The Chillum forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
When are sunrise and sunset in Chillum?
Today's sunrise and sunset times for Chillum 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 Chillum?
The next few days in Chillum's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.

Climate

In Chillum, Maryland, the warm-summer humid continental climate runs from about 32°F in January to 78°F in July, a 46°F seasonal range.

Across the year, Chillum collects about 42 inches of precipitation over roughly 175 days with measurable rain or snow.

Chillum's 46°F range, set by its 39.0°N position, drives frost timing and what thrives in Chillum.

All cities in Maryland →

Washington, DC weather →

ZIP codes in Chillum

  • 20783
  • 20782

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.