Temperatures across London are expected to cool in the coming week after the country experienced its hottest day of the year on Monday, but the warm sunshine is forecast to stick around for another day.

The hot period in the south and east is being replaced by a “westerly airflow” for the UK which will bring showers, longer spells of rain and a return to more average temperatures for the time of year.

A yellow heat health alert for London, issued by the UK Health Security Agency (UKHSA), will remain in force until 9am on Wednesday (August 14).

Here is the hour-by-hour for today (Tuesday)

10am – Sunny 19C

11am – Sunny 21C

12pm – Sunny 22C

1pm – Sunny 24C

2pm – Sunny 25C

3pm – Sunny 26C

4pm – Sunny 26C

5pm – Sunny 26C

6pm – Sunny 26C

7pm – Sunny 25C

8pm – Partly Cloudy 23C

9pm – Partly cloudy 22C

10pm - Partly cloudy 21C

11pm – Partly cloudy 20C

Here is the hour-by-hour forecast for tomorrow (Wednesday)

9am – Overcast 19C

10am – Overcast 20C

11am – Overcast 20C

12pm – Overcast 21C

1pm – Overcast 21C

2pm – Cloudy 22C

3pm – Sunny intervals 23C

4pm - Sunny intervals 23C

5pm - Sunny intervals 23C

6pm – Sunny intervals 24C

7pm - Sunny intervals 23C

8pm – Partly cloudy 22C

9pm – Clear 21C

10pm – Clear 20C

11pm – Clear 20C

Forecast in full

Today: Warm and humid to start, leading into a fine day with further sunny periods, although peak temperatures will be lower than on Monday. Becoming more generally cloudy in the west later. Maximum temperature 28 °C.

Tonight: Low cloud and a band of rain will make erratic inroads in from the west overnight, although eastern parts perhaps staying dry with clearer spells. Still warm and humid. Minimum temperature 12 °C.

Wednesday: Still warm and humid, but temperatures a notch down as cloud and a little rain edge erratically eastward and fade. Misty in southern coastal districts. Some limited brighter spells later. Maximum temperature 25 °C.

Outlook for Thursday to Saturday: Mainly fine again Thursday, ahead of some rain moving through southeast into Friday. Probably fine later Friday and into Saturday, but breezier than of late, with nearer-normal temperatures.

On Monday afternoon the Met Office posted on social media: “It’s been the hottest day of 2024 so far with 34.8°C recorded in Cambridge today.

“Provisionally this is only the 11th year since 1961 temperatures as high as this have been recorded.

“8 of those years have been since 2000 and 6 of them have been in the last decade.”

The UKHSA alert means those who are particularly vulnerable, such as the elderly with multiple health conditions, are likely to struggle to cope with the heat, and action may be required in the health and social care sector.

Caroline Abrahams, charity director of Age UK, said any older person living with health conditions should stay as cool as they can and advised friends and neighbours to offer help with picking up prescriptions or groceries.

The Met Office recommeds that people keep curtains closed during the peak of the day and drink a lot of water.