The yellow heat health alert has been issued for the entirety of the city from today (Monday, June 24) through to Thursday (June 27).
The alert has been issued by the UK Health Security Agency (UKHSA) in partnership with the Met Office.
According to the Met Office, a yellow health alert may be issued during periods of heat unlikely to impact most people with the exception of those who are particularly vulnerable.
These are people who are likely to struggle to cope in the heat.
Over the next few days, temperatures in London are set to reach highs of a whopping 29 degrees.
Today, the weather will be dry and warm with sunny spells.
The Met Office reports that there may be some patchy fog with a maximum temperature of 27 degrees.
Tonight, the Met Office forecasts dry and milk weather with the odd mist or fog patch developing.
On Tuesday (June 25), there are fog patches predicted early in the morning that will clear quickly.
As the day goes on, the weather is set to become very warm or even hot with lots of sunny spells.
The temperature should reach a high of 29 degrees.
In an outlook for the rest of the week, the Met Office forecasts dry, very warm or even hot weather with some sunny spells.
On Thursday evening, there may be a band of light rain and some cooler air on Friday.
We have put together an hour-by-hour forecast for today and tomorrow so that you can stay safe in the heat:
Monday, June 24
1pm – 25 degrees
2pm – 25 degrees
3pm – 26 degrees
4pm – 27 degrees
5pm – 27 degrees
6pm – 27 degrees
7pm – 26 degrees
8pm – 25 degrees
9pm – 24 degrees
10pm – 23 degrees
11pm – 22 degrees
Tuesday, June 25
5am – 18 degrees
6am – 18 degrees
7am – 19 degrees
8am – 20 degrees
9am – 21 degrees
10am – 23 degrees
11am – 24 degrees
12pm – 25 degrees
1pm – 26 degrees
2pm – 27 degrees
3pm – 28 degrees
4pm – 28 degrees
5pm – 28 degrees
6pm – 28 degrees
7pm – 27 degrees
8pm – 26 degrees
9pm – 24 degrees
10pm – 23 degrees
11pm – 22 degrees