Cardiff weather forecast: Sunny intervals and mild temperatures expected September 21, 2026

Cardiff, September 21, 2026 – Residents of Cardiff can expect a day of pleasant weather with sunny intervals and mild temperatures. The day will begin with a gentle start, gradually warming up to a comfortable maximum, making it an ideal day for most outdoor activities.The city is set to experience a day characterized by a mix of sunshine and cloud cover, with temperatures remaining mild throughout. While the chance of rain is minimal, a light shower is possible towards the end of the forecast period.Cardiff Weather TodayToday, September 21, 2026, Cardiff will see a high of 21°C and a low of 14°C, with an average temperature of 17.5°C. The day is expected to be largely dry, with a chance of rain less than 5%. Humidity levels will be relatively high, around 93%, contributing to a comfortable atmosphere. Wind speeds are expected to be around 19.31 kph. The condition is described as "Sunny intervals," suggesting a day with periods of sunshine interspersed with cloud cover. Sunrise is expected at 06:57 and sunset at 19:13.Enjoy the mild conditionsWith sunny intervals predicted for today, Cardiff residents can look forward to a pleasant day. The mild temperatures, with a high of 21°C, make it an excellent opportunity for outdoor pursuits. Whether it's a stroll through Bute Park or a visit to Cardiff Castle, the weather should be conducive. The low humidity and manageable wind speeds will add to the comfort. However, as the week progresses, there's a slight chance of light showers, so keeping an umbrella handy for later in the week might be a prudent decision.Cardiff Weather for Upcoming 7 DaysDateMax Temp (°C)Min Temp (°C)Avg Temp (°C)Condition2026-09-21211417.5Sunny intervals2026-09-22221518.5Sunny intervals2026-09-2321915.0Sunny intervals2026-09-24211317.0Sunny2026-09-25221418.0Sunny intervals2026-09-26201316.5Sunny intervals2026-09-27201417.0Light showersLooking ahead, Cardiff is expected to experience a week of predominantly sunny intervals, with temperatures hovering around the low 20s Celsius for the highs and mid-teens for the lows. The warmest days are anticipated on September 22nd and 25th, both reaching a high of 22°C. The coolest night is forecast for September 23rd, with temperatures dropping to 9°C. Towards the end of the week, on September 27th, there is a chance of light showers, marking a slight shift in the otherwise dry conditions. Overall, the upcoming week promises generally pleasant weather for the city.Source: Data referenced in this article is taken from the latest World News and Live updates. Download the TOI app.