Ilchester weather in September

In September, Ilchester sees average daytime highs of 78°F and overnight lows near 61°F, with 4.6 in of rain across 9.1 wet days and about 12.3 hours of daylight. It is the 4th-warmest and 1st-wettest month of the year here.

Highs ease over the month, from about 82°F in the first days to 73°F by the end. The sky is clear or mostly clear about 35% of the time in September, and the air most often feels dry.

Daylight stretches from about 12 h 54 min at the start of September to 11 h 36 min by month's end. Set against the rest of the year, September is Ilchester's 3rd-clearest and 9th-windiest month. For the whole year in context, see Ilchester's year-round climate.

Daytime high
78°
4th warmest
Overnight low
61°
9th coldest
Rainfall
4.6 in
9.1 wet days
Daylight
12 h 18 min
5:54 AM – 6:09 PM
Cloud cover
56%
3rd clearest
Wind
6 mph
9th windiest
Solar energy
4.27 kWh/m²
Travel score
6.9
out of 10

Ilchester is unincorporated community in Howard County, Maryland, United States.

Density
839/km²
people per km²
Founded
1761

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

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 82°F in the first days to 73°F by the end.

A typical September day in Ilchester reaches about 78°F in the afternoon and slips back to 61°F overnight — a 16°F spread between the day's warmth and the night's chill. On most days the high lands between 69°F and 87°F. Set against its neighbours, September runs about 7°F cooler than August and about 11°F warmer than October.

40°60°80°151015202530
Avg high (°F)Avg low (°F)
18266
28266
38266
48165
58165
68165
78065
88064
98064
108064
117963
127963
137862
147862
157862
167761
177761
187760
197660
207660
217659
227559
237559
247458
257458
267458
277357
287357
297356
307256

How September really feels in Ilchester

Once humidity and wind are folded in, September 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

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

Ilchester weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 1st-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan42° / 28°3.18.539.60.2
Feb44° / 29°2.98.53.210.50.9
Mar53° / 36°4.010.32.211.73.0
Apr64° / 47°3.510.30.2135.7
May73° / 56°3.811.4014.16.5
Jun82° / 65°3.711.6014.75.8
Jul86° / 70°4.212.1014.54.7
Aug84° / 69°3.710.9013.55.4
Sep78° / 61°4.69.1012.36.9
Oct66° / 50°3.680116.4
Nov55° / 39°3.07.60.29.83.8
Dec46° / 32°3.791.79.31.2

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 35% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 16% of September, with mostly cloudy or overcast conditions the remaining 48%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15446
25446
35446
45446
55545
65446
75446
85446
95446
105446
115347
125347
135248
145248
155149
165149
175050
184951
194852
204852
214951
224951
234852
244951
254951
265149
275248
285347
295446
305446

Chance of precipitation in September

Any precipitation

Ilchester gets around 4.6 in of rain over 9.1 wet days in September, the wettest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 29% and peaks near 31% on the wettest days.

0%10%20%30%40%151015202530
Rain chance (%)
131
231
331
431
531
631
731
830
930
1029
1128
1228
1327
1427
1527
1627
1727
1827
1927
2028
2128
2228
2329
2429
2529
2629
2729
2829
2929
3028

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the dry band about 34% of days. Sticky, muggy-or-worse air turns up on roughly 25% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
116192426151
217192425151
318202324141
419202324141
520202323131
622212222121
723212222121
824212221111
925212221101
102721222090
112820222090
122920232080
133120231970
143219231960
153419231960
163519231850
173618231840
183718231740
193918231740
204018221730
214118221630
224318211620
234418211520
244618201520
254718201410
264818191410
275018181310
285117181310
295217171310
305417161210

Wind in September

Winds average 6 mph in September.

Across September, 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.

0246810151015202530
Wind speed (mph)Feels
16calm
26calm
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
307calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 54 min at the start of September to 11 h 36 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 78 minutes over September. Sunrise moves from 5:40 AM to 6:07 AM, and sunset from 6:34 PM to 5:46 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.95:406:34
212.95:416:32
312.85:426:31
412.85:436:29
512.75:436:27
612.75:446:26
712.65:456:24
812.65:466:22
912.65:476:21
1012.55:486:19
1112.55:496:17
1212.45:506:16
1312.45:516:14
1412.35:526:12
1512.35:536:11
1612.35:546:09
1712.25:556:07
1812.25:566:06
1912.15:576:04
2012.15:586:02
2112.05:596:01
2212.05:595:59
2311.96:005:57
2411.96:015:55
2511.96:025:54
2611.86:035:52
2711.86:045:50
2811.76:055:49
2911.76:065:47
3011.66:075:46

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.27 kWh/m².

For context, solar energy here swings from a low near 1.92 kWh/m² to a high of 6.11 kWh/m² in June across the year — September's 4.27 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.8Bright
24.8Bright
34.8Bright
44.7Bright
54.7Bright
64.7Bright
74.6Bright
84.6Bright
94.5Bright
104.5Bright
114.5Bright
124.4Bright
134.4Bright
144.4Bright
154.3Bright
164.3Bright
174.3Bright
184.2Bright
194.2Bright
204.1Bright
214.1Bright
224.0Bright
234.0Bright
244.0Moderate
253.9Moderate
263.9Moderate
273.9Moderate
283.8Moderate
293.8Moderate
303.8Moderate
Planning a trip in September

Hazard calendar for Ilchester

In seasonPeak

In September, Ilchester sits inside its atlantic hurricane season. The full year is below, with each hazard's peak months called out.

Ilchester sits in the Atlantic hurricane belt; the season peaks August–October.

Atlantic hurricane
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is September a good time to visit Ilchester?

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

6.9
Sightseeing
1st-best month of the year
6.3
Beach & pool
4th-best month of the year

September is a reasonable time to visit Ilchester for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Ilchester in September

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

In September, Ilchester sees daytime highs around 78°F and nights near 61°F. Worth packing: light clothes and rain gear. About 9 days see rain.

light clothesrain gear

Sea temperature near Ilchester in September

The nearest coast averages about 74°F in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 22 mi away) is warmest in August at about 78°F and coldest in February near 36°F.

It's comfortable for a long swim from Jun 16 to Oct 5 — about 3.7 months when the water holds above 68°F.

30°40°50°60°70°80°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°F)Comfort
Jan38Bracing
Feb36Bracing
Mar40Bracing
Apr47Bracing
May58Bracing
Jun68Refreshing
Jul76Warm
Aug78Warm
Sep74Refreshing
Oct65Cool
Nov53Bracing
Dec44Bracing

UV index in Ilchester in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 6 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Ilchester 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
Mar5Moderate
Apr6High
May8Very high
Jun9Very high
Jul9Very high
Aug7High
Sep6High
Oct4Moderate
Nov3Moderate
Dec2Low

Air quality in Ilchester in September

GoodModeratePoorUnhealthyVery unhealthy

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

Air quality in Ilchester is worst in July — around 17 µg/m³ PM2.5 (moderate), about 2.0× the cleanest month (November, 8 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1216 µg/m³Nov 118 µg/m³
PM2.5 (µg/m³)Level
Jan10Good
Feb12Good
Mar13Moderate
Apr13Moderate
May15Moderate
Jun16Moderate
Jul17Moderate
Aug14Moderate
Sep12Good
Oct9Good
Nov8Good
Dec10Good
Location & terrain

Where is Ilchester?

Ilchester sits at 39.3°N, 76.8°W, 108 ft above sea level, in United States. The nearest listed city is Ellicott City, 1.9 mi away.

Topography around Ilchester

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

Within 2 miles, the terrain around Ilchester has only modest variations in elevation — a maximum elevation change of 518 ft around an average of 390 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 735 ft; within 50 miles, large variations in elevation — a maximum elevation change of 2,031 ft.

The land around Ilchester is covered by trees (83%) within 2 miles, trees (61%) and artificial surfaces (25%) within 10 miles, and trees (54%) within 50 miles.

2 miles
518 ft
10 miles
735 ft
50 miles
2,031 ft
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Ellicott City 1.9 mi · Catonsville 2.5 mi · Arbutus 3.7 mi · West Elkridge 3.7 mi · Elkridge 3.7 mi · Columbia 4.3 mi · Hanover 4.3 mi · Woodlawn 5.6 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 Ilchester (39.2509°, -76.7647°, elevation 108 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. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. 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).