What Hounslow weather does to a conservatory
The grid reads like a calendar turned on its side: months down, hours across, colour for the average room temperature. Hounslow's warmest month outdoors was July at 18.9°C on average, with a top of 33.5°C, yet a polycarbonate conservatory peaked at 49°C because the roof traps the midday sun.
A year inside a Hounslow conservatory
Average room temperature, every month and hour of 2024 and 2025
- 1,501
- hours over 25°C
- 49°C
- hottest hour
- 34°C
- July, 3pm
- 1,642
- hours over 25°C
- 52°C
- hottest hour
- 36°C
- July, 3pm
- 481
- hours over 25°C
- 36°C
- hottest hour
- 26°C
- July, 3pm
Blue: heater weatherPale: comfortableAmber to plum: too warm
The hours you get back
A heater can rescue a chilly hour. Nothing cheap rescues a 31°C one. So the useful measure is how many waking hours stay at or under 25°C: in Hounslow that is 3,612 a year under polycarbonate and 4,633 under an insulated panel roof, roughly 1,021 hours handed back.
The worst hours, above 30°C, fall from 721 to 86. A glass roof manages 879.
- Polycarbonate roof1,501 h too warm
- Glass roof1,642 h too warm
- Panel roof481 h too warm
Too cold (under 12°C)Chilly (12 to 17°C)Comfortable (17 to 25°C)Warm (25 to 28°C)Too hot (over 28°C)
When the heat peaks in Hounslow
June is the problem month here: 53% of its waking hours top 28°C under polycarbonate, 14% under panels. Spring and early autumn matter too, when the sun is still strong but nobody expects to open the doors.
Polycarbonate roofInsulated panel roof
Winter in Hounslow
Winter here bottoms out in January at an average of 4.5°C (coldest hour -4.8°C). Keeping 19°C while the room is in use costs about £383 a year in electricity under polycarbonate and £329 under the panel roof, 1,457 against 1,250 kWh.
We would not sell the roof on that difference alone. The glass walls keep losing heat either way; what changes most is that the room stops cooking in summer and a smaller heater copes in winter.
Prices for Hounslow conservatory roofs
There is no Hounslow premium: size and shape decide the price. The survey is free and the written price is fixed. See the price page for every shape, or get a guide price for your roof in about a minute.
| Shape | Small (up to 12 m²) | Medium (12 to 25 m²) | Large (over 25 m²) |
|---|---|---|---|
| Lean-to | from £3,000 | from £4,000 | from £5,000 |
| Edwardian | from £3,150 | from £4,200 | from £5,250 |
| Victorian | from £3,300 | from £4,400 | from £5,500 |
Fitting day
Plan on a single day for most Hounslow roofs, usually a second for a P-shape. We take the old roof away the same day and leave the room swept. The fitting day walks through it hour by hour.
Towns near Hounslow
Compare your neighbours, or see all of Greater London and the full overheating league table.