Cardiff weather September 18 2026: Cloudy skies, high humidity, and mild temperatures expected

Cardiff residents can expect a day of predominantly cloudy skies today, September 18, 2026, with a moderate chance of rain. Temperatures will be mild, with a high of 18°C and a low of 16°C. The humidity will be notably high, reaching 88%, which may make the air feel damp.The day's weather is characterized by a significant amount of cloud cover, contributing to the elevated humidity levels. While the chance of precipitation is less than 5%, the overcast conditions suggest a possibility of light showers or drizzle throughout the day. The maximum wind speed is forecast to be around 51.5 kph, which could bring a noticeable breeze.Cardiff Weather TodayToday, September 18, 2026, Cardiff will experience a cloudy day with a high temperature of 18°C and a low of 16°C. The average temperature for the day is expected to be around 17.0°C. A significant factor for today will be the high humidity, which is predicted to be 88%. This elevated moisture in the air, combined with the cloudy conditions, means that the weather might feel rather muggy.The chance of rain today is less than 5%, so significant downpours are unlikely. However, the presence of clouds and high humidity could lead to some light precipitation or a persistent dampness in the air. Wind speeds are expected to reach a maximum of 51.5 kph, indicating a breezy day. The sunrise is scheduled for 06:53 and sunset for 19:20, providing a standard daylight period.Cloudy skies and high humidity expectedResidents of Cardiff should prepare for a day where umbrellas are not strictly necessary but might be useful for unexpected light drizzles. The high humidity of 88% means that the air will feel damp, and it might be advisable to wear breathable clothing. While the temperatures are mild, the combination of cloud cover and humidity could make it feel warmer than the thermometer suggests.The breezy conditions with winds up to 51.5 kph should be taken into account if planning outdoor activities that could be affected by wind. For those sensitive to humidity, it might be a day to stay indoors during the peak hours or ensure good ventilation. Overall, it's a day that calls for comfortable, layered clothing, with a slight preparedness for dampness.Cardiff Weather for Upcoming 7 DaysThe forecast for Cardiff indicates a mixed bag of weather conditions over the next seven days, with a general trend of improving conditions after today. Following today's cloudy and humid weather, tomorrow, September 19, is expected to bring light rain. Temperatures will remain mild, with a high of 19°C and a low of 14°C.The latter half of the week appears to be more settled and sunny. From September 20 to September 24, the city is forecast to experience sunny intervals. Temperatures are expected to gradually rise, with highs reaching up to 21°C on September 21 and 22. The low temperatures will hover around the mid-teens, generally between 12°C and 14°C. This period of sunny intervals suggests a pleasant shift in weather, making it more conducive for outdoor activities.DateMax Temp (C)Min Temp (C)Avg Temp (C)Condition2026-09-18181617.0Cloudy2026-09-19191416.5Light rain2026-09-20201517.5Sunny intervals2026-09-21211317.0Sunny intervals2026-09-22211417.5Sunny intervals2026-09-23191215.5Sunny intervals2026-09-24191416.5Sunny intervalsThe week ahead in Cardiff will transition from a damp and cloudy start to a period of increasing sunshine and mild temperatures.Source: Data referenced in this article is taken from the latest World News and Live updates. Download the TOI app.