Runcorn weather in September

In September, Runcorn sees average daytime highs of 17°C and overnight lows near 11°C, with 69 mm of rain across 12.1 wet days and about 12.4 hours of daylight. It is the 4th-warmest and 7th-wettest month of the year here.

Highs ease over the month, from about 18°C in the first days to 16°C by the end. The sky is clear or mostly clear about 9% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 h 30 min at the start of September to 11 h 24 min by month's end. Set against the rest of the year, September is Runcorn's 6th-clearest and 9th-windiest month. For the whole year in context, see Runcorn's year-round climate.

Daytime high
17°
4th warmest
Overnight low
11°
9th coldest
Rainfall
69 mm
12.1 wet days
Daylight
12 h 24 min
5:53 AM – 6:18 PM
Cloud cover
74%
6th clearest
Wind
13 km/h
9th windiest
Solar energy
2.86 kWh/m²
Travel score
5.0
out of 10

Runcorn is town in Cheshire, England, UK.

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 18°C in the first days to 16°C by the end.

A typical September day in Runcorn reaches about 17°C in the afternoon and slips back to 11°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 14°C and 21°C. Set against its neighbours, September runs about 2°C cooler than August and about 3°C warmer than October.

10°15°20°25°151015202530
Avg high (°C)Avg low (°C)
11912
21812
31812
41812
51811
61811
71811
81811
91811
101811
111811
121811
131811
141711
151711
161711
171711
181711
191710
201710
211710
221710
231710
241610
251610
261610
271610
281610
291610
301610

How September really feels in Runcorn

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.

Runcorn weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 7th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / 6213.317.81.0
Feb / 54121.19.41.2
Mar10° / 5912.30.711.52.1
Apr13° / 6312.50.313.73.2
May16° / 6712.4015.64.4
Jun18° / 11°8013.2016.65.2
Jul20° / 13°8314.1016.25.5
Aug20° / 13°8314.1014.65.4
Sep17° / 11°6912.1012.45.0
Oct14° / 7213.4010.33.6
Nov10° / 7013.70.18.42.0
Dec / 7313.90.87.41.1

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 9% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 18% of September, with mostly cloudy or overcast conditions the remaining 74%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
12872
22971
32971
42971
53070
63070
72971
82971
92971
102872
112872
122872
132773
142773
152773
162773
172674
182674
192575
202575
212575
222575
232575
242377
252476
262476
272476
282476
292476
302476

Chance of precipitation in September

Any precipitation

Runcorn gets around 69 mm of rain over 12.1 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 41% and peaks near 43% on the wettest days.

0%10%20%30%40%50%151015202530
Rain chance (%)
138
238
338
439
539
640
740
840
941
1041
1141
1241
1341
1441
1541
1641
1741
1841
1941
2041
2140
2240
2341
2441
2541
2642
2742
2843
2943
3043

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 81% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)
169274
270264
371263
472253
573243
674233
775223
875223
976213
1077203
1179192
1280182
1381172
1482162
1583161
1684151
1784151
1885141
1985141
2085141
2186140
2286140
2386140
2486140
2586140
2687130
2787130
2888120
2988120
3089110

Wind in September

Winds average 13 km/h in September.

Across September, daily wind ranges from about 13 km/h on the calmest days to 14 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202530
Wind speed (km/h)Feels
113light breeze
213light breeze
313light breeze
413light breeze
513light breeze
613light breeze
713light breeze
813light breeze
913light breeze
1013light breeze
1113light breeze
1213light breeze
1313light breeze
1413light breeze
1513light breeze
1613light breeze
1713light breeze
1813light breeze
1913light breeze
2013light breeze
2113light breeze
2214light breeze
2314light breeze
2414light breeze
2514light breeze
2614light breeze
2714light breeze
2814light breeze
2914light breeze
3014light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 h 30 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 126 minutes over September. Sunrise moves from 5:26 AM to 6:18 AM, and sunset from 6:55 PM to 5:42 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.55:266:55
213.45:286:53
313.35:306:50
413.35:316:48
513.25:336:45
613.15:356:43
713.15:376:40
813.05:386:38
912.95:406:35
1012.85:426:33
1112.85:446:30
1212.75:466:28
1312.65:476:25
1412.65:496:23
1512.55:516:20
1612.45:536:18
1712.35:556:15
1812.35:566:13
1912.25:586:10
2012.16:006:08
2112.16:026:05
2212.06:046:02
2311.96:056:00
2411.86:075:57
2511.86:095:55
2611.76:115:52
2711.66:135:50
2811.56:145:47
2911.56:165:45
3011.46:185:42

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 2.86 kWh/m².

For context, solar energy here swings from a low near 0.53 kWh/m² to a high of 5.12 kWh/m² in June across the year — September's 2.86 kWh/m² falls in the middle.

01234151015202530
Solar energy (kWh/m²)Level
13.5Moderate
23.4Moderate
33.4Moderate
43.4Moderate
53.3Moderate
63.3Moderate
73.2Moderate
83.2Moderate
93.1Moderate
103.1Moderate
113.1Moderate
123.0Moderate
133.0Moderate
142.9Moderate
152.9Moderate
162.8Moderate
172.8Moderate
182.7Moderate
192.7Moderate
202.6Moderate
212.6Moderate
222.5Moderate
232.5Moderate
242.5Moderate
252.4Moderate
262.4Moderate
272.3Moderate
282.3Moderate
292.2Moderate
302.2Moderate
Planning a trip in September

Is September a good time to visit Runcorn?

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

5.0
Sightseeing
4th-best month of the year
1.3
Beach & pool
4th-best month of the year

September is a reasonable time to visit Runcorn for sightseeing.

What to pack for Runcorn in September

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

In September, Runcorn sees daytime highs around 17°C and nights near 11°C. Worth packing: rain gear. About 12 days see rain.

rain gear

Sea temperature near Runcorn in September

The nearest coast averages about 16°C 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 26 km away) is warmest in August at about 17°C and coldest in February near 6°C.

The water stays below 20°C all year — cool enough that most swimmers want a wetsuit.

5°10°15°20°JanFebMarAprMayJunJulAugSepOctNovDecbracingcool
Sea temperature (°C)Comfort
Jan7Bracing
Feb6Bracing
Mar7Bracing
Apr9Bracing
May11Bracing
Jun14Bracing
Jul16Cool
Aug17Cool
Sep16Cool
Oct14Bracing
Nov11Bracing
Dec9Bracing

UV index in Runcorn 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 Runcorn peaks around August 13 at about 6 (high) — a little sun protection helps at midday. 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 13UV 6Jan 1UV 1
UV index (midday)Level
Jan1Low
Feb1Low
Mar3Moderate
Apr3Moderate
May5High
Jun6High
Jul5High
Aug6High
Sep4Moderate
Oct2Low
Nov1Low
Dec1Low
Location & terrain

Where is Runcorn?

Runcorn sits at 53.3°N, 2.7°W, 18 m above sea level, in United Kingdom. The nearest listed city is Widnes, 2.0 km away.

Topography around Runcorn

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

Within 3 km, the terrain around Runcorn has only modest variations in elevation — a maximum elevation change of 95 m around an average of 24 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 173 m; within 80 km, large variations in elevation — a maximum elevation change of 823 m.

The land around Runcorn is covered by artificial surfaces (38%), trees (26%) and water (22%) within 3 km, grassland (28%), trees (27%) and artificial surfaces (20%) within 16 km, and grassland (52%) within 80 km.

3 km
95 m
16 km
173 m
80 km
823 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Widnes 2.0 km · Halewood 7.0 km · Speke 7.0 km · Great Sankey 8.0 km · Hunts Cross 9.0 km · Belle Vale 10 km · Huyton 11 km · Prescot 11 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 Runcorn (53.3417°, -2.7312°, elevation 18 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. 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. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).