worldweather20°Cwarmer than usual
usually 17°C–21°C
warmer than 73% of similar days
night: exceptionally warm
rain: typical rainfall
wind: typical
Weather in Cardiff - 14-day forecast
Detailed weather forecast for Cardiff, United Kingdom: daytime and night temperature, rain, sunrise and sunset - today and for the next two weeks.
Forecast for the next days in Cardiff
today🌤️
20°💧 0.2 mm
Sun🌤️
24°💧 1.3 mm
Mon🌧️
18°💧 1.7 mm
Tue🌧️
17°💧 3.9 mm
Wed🌧️
16°💧 0.5 mm
Thu🌧️
20°💧 1.2 mm
Fri🌤️
19°💧 1.6 mm
Sat🌧️
13°💧 11.3 mm
Forecast vs 1991-2020 climate normal
NASA POWERHow does the current forecast compare with normal?
We compare the coming days with weather usually observed at this time of year.
Sunday 6 Sept in Cardiff, the forecast high is 24°C. Typical daytime temperatures at this time of year range from 17°C to 21°C, so it will be exceptionally warm. It is warmer than 97% of similar days.
24°Cexceptionally warm
usually 17°C–21°C
warmer than 97% of similar days
night: exceptionally warm
rain: typical rainfall
wind: typical
18°Cnear normal
usually 17°C–20°C
night: exceptionally warm
rain: typical rainfall
wind: stronger than usual
17°Cnear normal
usually 17°C–20°C
night: warmer than usual
rain: more rain than usual
wind: stronger than usual
16°Ccooler than usual
usually 16°C–20°C
cooler than 81% of similar days
night: exceptionally warm
rain: typical rainfall
wind: typical
20°Cwarmer than usual
usually 16°C–20°C
warmer than 75% of similar days
night: exceptionally warm
rain: typical rainfall
wind: stronger than usual
19°Cnear normal
usually 16°C–20°C
night: warmer than usual
rain: typical rainfall
wind: typical
How warm was this week in previous years?
Each bar shows the average daily high during the same 7-day period in each year.
cooler yearstypical rangewarmer years2026 forecastcurrent forecast
From 1981 to 2025, the 5-11 Sept period averaged 19°C by day. The coolest year was 1994 (16°C) and the warmest was 2023 (25°C). The current forecast averages 19°C - higher than in 67% of historical years.
Historical reference: NASA POWER daily gridded data (MERRA-2), the 1991-2020 normal and a +/- 7-day calendar window. The typical range is the 20th-80th percentile. This is not a city weather-station reading and does not change the current forecast. NASA POWER Daily API.
14-day forecast - Cardiff
Cardiff 30 & 45-day weather - long-range outlook
Next 16 days · forecast
19°
around 15° at night · days with rain: 11
Weeks 3-4 · avg for September
18°
around 12° at night · rain chance 53%
Weeks 5-7 · avg for October
15°
around 10° at night · rain chance 63%
The 30 & 45-day outlook for Cardiff: the next 16 days are a numerical forecast updated daily - on average 19° by day and 15° at night. Further out we rely on multi-year climate averages: around 18° in September, and about 15° in October. Forecasts beyond two weeks are indicative only.
Day-by-day forecast for Cardiff
Saturday5 September 2026
🌤️20°scattered clouds
Sunday6 September 2026
🌤️24°scattered clouds
Monday7 September 2026
🌧️18°moderate rain
Tuesday8 September 2026
🌧️17°moderate rain
Wednesday9 September 2026
🌧️16°light rain
Thursday10 September 2026
🌧️20°light rain
Friday11 September 2026
🌤️19°scattered clouds
Saturday12 September 2026
🌧️13°light rain
Sunday13 September 2026
🌧️19°light rain
Monday14 September 2026
☀️18°clear sky
Tuesday15 September 2026
🌤️19°scattered clouds
Wednesday16 September 2026
🌧️20°light rain
Thursday17 September 2026
🌧️20°light rain
Friday18 September 2026
🌧️20°light rain
Saturday19 September 2026
🌧️17°light rain
Sunday20 September 2026
🌧️17°light rain
UV index in Cardiff - is it safe to sunbathe?
Today the UV index in Cardiff is 4 (moderate) - unprotected fair skin can burn in about 55 minutes. Seek shade around midday. SPF 30+, sunglasses and a hat for longer stays.
Sea temperature - Cardiff
Water today
20°C
Week avg
20°C
Waves today
0.7 m
How's the water?
brisk
16-day sea temperature forecast:
Average sea temperature through the year:
Sea-surface temperature from marine models, updated daily. See also: where the sea is warmest right now.
Air quality and smog in Cardiff
Air quality in Cardiff is currently very good. Fine particulate PM2.5: 4.4 µg/m³, PM10: 12.3 µg/m³.
| City | PM2.5 (µg/m³) | PM10 (µg/m³) | Air quality |
|---|---|---|---|
| Cardiff | 4.4 | 12.3 | very good |
Based on PM2.5 thresholds. Station readings, updated daily (last reading: 2026-09-05, 02:00).
Cardiff weather through the year
Warmest, driest months on average: April, May, June, July.
Upcoming public holidays in United Kingdom: Christmas Day — 25 December · Boxing Day — 28 December · New Year's Day — 1 January.
Nearby and related places
FAQ - Cardiff weather
What is the weather like in Cardiff today?
Today it is about 20° during the day and 16° at night, scattered clouds.
How far ahead can I check the forecast for Cardiff?
This page shows a detailed 14-day forecast plus the long-term monthly climate, so you can plan both a short trip and a holiday months ahead.