Hertfordshire looks likely to see yet another spell of very warm weather as meteorological models point to a fifth heatwave of the summer for much of eastern and southern England. Local forecasts indicate Watford could reach about 31C on Monday, while model outputs suggest temperatures might climb even higher later in August.
What the models show
Data from the GFS weather model lists Hertfordshire among 11 counties that could reach official heatwave levels later this month. Model runs give a maximum possible temperature of up to 35C on 12 August, though the Met Office cautions that the pattern remains changeable and there is still a chance of rain.
“A generally rather changeable period looks likely, with many places likely to see some much needed rain or showers at times but also some more sunshine,”
The Met Office adds that initially some rain or heavy, possibly thundery showers may affect many areas before drier, brighter conditions return for a short spell. It warns that further unsettled conditions could develop towards mid‑August as weather fronts arrive from the Atlantic or warmer plumes move north from the continent.
Heatwave threshold and local context
An official heatwave in the south‑east is declared when daily maximum temperatures reach the local heatwave threshold of 28C for three consecutive days. If the GFS projections are realised, Hertfordshire could meet that threshold again later this month.
The forecast comes against a summer of exceptionally low rainfall: nationally, the season so far has recorded around 7% of expected rainfall, falling to approximately 1% in southern England. That shortfall has already led to formal drought measures in the county and the introduction of a hosepipe ban.
Local impact and what residents should know
The combination of intense heat and ongoing drought raises several practical concerns for residents and local services:
- Water supply: the hosepipe ban remains in place; residents should continue conserving water and check Affinity Water guidance for permitted and banned uses.
- Vulnerable people: prolonged high temperatures increase risks for the elderly, very young children and those with long‑term health conditions; staying hydrated and avoiding strenuous activity in the hottest hours is advised.
- Outdoor workers and events: employers and event organisers should consider heat‑risk measures, such as shaded rest areas and extra breaks.
| Item | Value |
|---|---|
| Watford forecast (Monday) | 31C |
| GFS model peak shown | 35C (12 August) |
| South‑east heatwave threshold | 28C for three days |
Local authorities have been monitoring river flows, groundwater and reservoir levels. The drought declaration and the hosepipe ban are measures intended to protect supplies for essential uses as the region faces another period of potentially high temperatures and continued water stress.
Forecasters stress that model projections can change as new data arrives, so residents should keep an eye on updates from the Met Office and local councils. For practical advice on staying safe during heat and information about current water restrictions, check guidance published by Hertfordshire County Council and Affinity Water.
With the summer so far unusually dry, even a short spell of very hot weather can add pressure on services and the natural environment. Households and businesses are being urged to plan for short‑term heat while remaining ready for sudden changes in the weather pattern.
