Stevenage weather in September

In September, Stevenage sees average daytime highs of 18°C and overnight lows near 11°C, with 51 mm of rain across 9 wet days and about 12.4 hours of daylight. It is the 4th-warmest and 9th-wettest month of the year here.

Highs ease over the month, from about 20°C in the first days to 17°C by the end. The sky is clear or mostly clear about 13% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 h 24 min at the start of September to 11 h 24 min by month's end. Set against the rest of the year, September is Stevenage's 5th-clearest and 9th-windiest month. For the whole year in context, see Stevenage's year-round climate.

Daytime high
18°
4th warmest
Overnight low
11°
9th coldest
Rainfall
51 mm
9 wet days
Daylight
12 h 24 min
5:43 AM – 6:07 PM
Cloud cover
70%
5th clearest
Wind
15 km/h
9th windiest
Solar energy
2.97 kWh/m²
Travel score
5.8
out of 10

Stevenage is town in Hertfordshire, England.

Density
3,535/km²
people per km²

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 20°C in the first days to 17°C by the end.

A typical September day in Stevenage reaches about 18°C in the afternoon and slips back to 11°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 15°C and 22°C. Set against its neighbours, September runs about 3°C cooler than August and about 4°C warmer than October.

10°15°20°25°151015202530
Avg high (°C)Avg low (°C)
12012
22012
32012
42012
51912
61911
71911
81911
91911
101911
111911
121911
131911
141811
151811
161811
171811
181811
191811
201810
211810
221810
231710
241710
251710
261710
271710
281710
291710
301610

How September really feels in Stevenage

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

Days feeling ≥ 32°C
0
heat index over the day's high
Days feeling ≤ C
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.

Stevenage weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 9th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / 5211.10.98.10.8
Feb / 429.71.39.61.1
Mar10° / 4310.40.811.52.2
Apr13° / 5011.40.213.63.4
May16° / 5610.8015.44.8
Jun19° / 11°5910.4016.45.8
Jul21° / 13°6011.50166.2
Aug21° / 13°6310.7014.46.2
Sep18° / 11°519012.45.8
Oct14° / 5810.7010.44.0
Nov10° / 5810.90.28.62.2
Dec / 54110.97.61.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 13% 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 70%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
13268
23268
33268
43367
53466
63466
73466
83367
93367
103268
113268
123169
133169
143070
152971
162971
172872
182773
192773
202773
212773
222674
232674
242773
252773
262872
272773
282872
292872
302872

Chance of precipitation in September

Any precipitation

Stevenage gets around 51 mm of rain over 9 wet days in September. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 31% and peaks near 37% on the wettest days. The odds climb toward the end of the month.

0%10%20%30%40%50%151015202530
Rain chance (%)
127
227
326
426
526
626
726
827
927
1027
1128
1228
1329
1429
1529
1630
1730
1831
1932
2032
2133
2233
2334
2434
2535
2636
2736
2837
2937
3037

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 79% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)
172244
273234
373234
473234
574224
674224
775214
875214
976204
1076204
1177194
1278193
1379183
1479183
1579183
1680182
1780182
1880182
1981181
2081181
2181181
2280191
2380191
2482180
2582180
2682180
2783170
2883170
2984160
3084160

Wind in September

Winds average 15 km/h in September.

Across September, daily wind ranges from about 14 km/h on the calmest days to 15 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202530
Wind speed (km/h)Feels
114light breeze
214light breeze
314light breeze
414light breeze
514light breeze
614light breeze
714light breeze
815light breeze
915light breeze
1015light breeze
1115light breeze
1215light breeze
1315light breeze
1415light breeze
1515light breeze
1615light breeze
1715light breeze
1815light breeze
1915light breeze
2015light breeze
2115light breeze
2215light breeze
2315light breeze
2415light breeze
2515light breeze
2615light breeze
2715light breeze
2815light breeze
2915light breeze
3015light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 h 24 min at the start of September to 11 h 24 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 120 minutes over September. Sunrise moves from 5:18 AM to 6:07 AM, and sunset from 6:43 PM to 5:33 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.45:186:43
213.35:206:41
313.35:226:38
413.25:236:36
513.15:256:33
613.15:276:31
713.05:286:29
812.95:306:26
912.95:326:24
1012.85:336:21
1112.75:356:19
1212.75:376:17
1312.65:386:14
1412.55:406:12
1512.55:426:09
1612.45:436:07
1712.35:456:05
1812.35:476:02
1912.25:486:00
2012.15:505:57
2112.15:525:55
2212.05:535:52
2311.95:555:50
2411.85:575:48
2511.85:595:45
2611.76:005:43
2711.66:025:40
2811.66:045:38
2911.56:055:36
3011.46:075:33

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 2.97 kWh/m².

For context, solar energy here swings from a low near 0.62 kWh/m² to a high of 5.13 kWh/m² in June across the year — September's 2.97 kWh/m² falls in the middle.

01234151015202530
Solar energy (kWh/m²)Level
13.5Moderate
23.5Moderate
33.5Moderate
43.4Moderate
53.4Moderate
63.4Moderate
73.3Moderate
83.3Moderate
93.2Moderate
103.2Moderate
113.2Moderate
123.1Moderate
133.1Moderate
143.0Moderate
153.0Moderate
162.9Moderate
172.9Moderate
182.8Moderate
192.8Moderate
202.8Moderate
212.7Moderate
222.7Moderate
232.6Moderate
242.6Moderate
252.5Moderate
262.5Moderate
272.5Moderate
282.4Moderate
292.4Moderate
302.3Moderate
Planning a trip in September

Is September a good time to visit Stevenage?

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

5.8
Sightseeing
3rd-best month of the year
2.1
Beach & pool
4th-best month of the year

September is a reasonable time to visit Stevenage for sightseeing.

What to pack for Stevenage in September

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

In September, Stevenage sees daytime highs around 18°C and nights near 11°C. Worth packing: rain gear. About 9 days see rain.

rain gear

UV index in Stevenage in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 4 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Stevenage peaks around August 10 at about 6 (high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near January 1 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 6 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighModerateLowAug 10UV 6Jan 1UV 1
UV index (midday)Level
Jan1Low
Feb1Low
Mar3Moderate
Apr3Moderate
May5High
Jun6High
Jul6High
Aug6High
Sep4Moderate
Oct2Moderate
Nov1Low
Dec1Low
Location & terrain

Where is Stevenage?

Stevenage sits at 51.9°N, 0.2°W, 94 m above sea level, in United Kingdom. The nearest listed city is Hitchin, 8.0 km away.

Topography around Stevenage

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Stevenage.

Within 3 km, the terrain around Stevenage has only modest variations in elevation — a maximum elevation change of 79 m around an average of 107 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 161 m; within 80 km, significant variations in elevation — a maximum elevation change of 317 m.

The land around Stevenage is covered by artificial surfaces (33%) and trees (29%) within 3 km, cropland (47%), grassland (23%) and trees (21%) within 16 km, and cropland (42%) and grassland (26%) within 80 km.

3 km
79 m
16 km
161 m
80 km
317 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Hitchin 8.0 km · Letchworth Garden City 9.0 km · Welwyn Garden City 11 km · Harpenden 14 km · Hertford 15 km · Luton 15 km · Hatfield 16 km · Ware 16 km

United Kingdom travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type D / G / M
230 V · 50 Hz
Prices
≈ 89% of US
price level, 2025
GDP per capita
$57,602
2025
Happiness
6.7 / 10
World Happiness, 2025
Safe drinking water
100%
of population, 2024
Homicide rate
1.1
per 100k, 2021
Road deaths
3.2
per 100k/yr, 2019
Income group
High
World Bank
Religion
Christian 60%none 26%Muslim 4%other 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 Stevenage (51.9022°, -0.2026°, elevation 94 m), 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. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).