Daily profile
How the weather typically changes through the day: the average at every time of day, from each clean minute of station data since 2011. Pick a variable, then a year, a month (that month in every year), or both. The dashed line compares a year or month with the long-term profile. Drag across the chart to zoom in.
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Data quality
Only the station's own, well-performing data is used. Whole days are left out for a variable when its sensor was faulty, drifting or stalled, when another station's data was filled in, on clock-change days, and when the station notes report a fault. Within each day, repeated or slow (externally filled) feed rows, flatlines, spikes and out-of-range readings are removed minute by minute, and days with too little clean data left are dropped.
| Variable | From | Days used | Coverage | Main reasons days were left out |
|---|---|---|---|---|
| Temperature | Jan 2011 | 5,602 of 5,784 | 96.9% | Station notes for the day report a fault, data loss or substitute data (83); Known sensor fault, drift or substitute-source period (45); Clock-change day (the 01:00 hour is missing or doubled) (32) |
| Dew point | Jan 2011 | 4,213 of 5,784 | 72.8% | Known sensor fault, drift or substitute-source period (1,435); Station notes for the day report a fault, data loss or substitute data (83); Clock-change day (the 01:00 hour is missing or doubled) (32) |
| Humidity | Jan 2011 | 4,213 of 5,784 | 72.8% | Known sensor fault, drift or substitute-source period (1,452); Station notes for the day report a fault, data loss or substitute data (72); Clock-change day (the 01:00 hour is missing or doubled) (32) |
| Pressure | Jan 2011 | 5,650 of 5,784 | 97.7% | Station notes for the day report a fault, data loss or substitute data (59); Clock-change day (the 01:00 hour is missing or doubled) (32); Stale or externally filled feed for 2+ hours (19) |
| Wind speed | Jan 2011 | 5,158 of 5,784 | 89.2% | Known sensor fault, drift or substitute-source period (475); Station notes for the day report a fault, data loss or substitute data (86); Clock-change day (the 01:00 hour is missing or doubled) (32) |
| Gust speed | Jan 2011 | 5,158 of 5,784 | 89.2% | Known sensor fault, drift or substitute-source period (475); Station notes for the day report a fault, data loss or substitute data (86); Clock-change day (the 01:00 hour is missing or doubled) (32) |
| Rain rate | Jan 2011 | 5,316 of 5,784 | 91.9% | Known sensor fault, drift or substitute-source period (211); Station notes for the day report a fault, data loss or substitute data (140); Minute log incomplete (rain needs a near-complete day) (48) |
| Raining (% of time) | Apr 2014 | 4,180 of 4,598 | 90.9% | Known sensor fault, drift or substitute-source period (211); Station notes for the day report a fault, data loss or substitute data (116); Minute log incomplete (rain needs a near-complete day) (37) |
| Sunshine (% of time) | Sep 2021 | 1,570 of 1,882 | 83.4% | Known sensor fault, drift or substitute-source period (155); Webcam sunshine classified for under 90% of daylight (96); Webcam model total far from the day's sunshine total (61) Of the days used, 1,297 are model-estimated from webcam (2021, 2022, 2023, 2024, 2025) |
Periods left out
- 22 Aug 2011 – 29 Aug 2011 (wind): Logger download, not live feed: gusts unreliable
- 15 Dec 2011 – 21 Dec 2011 (wind): Wind sensor failure; rebuilt from nearby sites
- 6 May 2015 – 11 May 2015 (wind): Wind sensor battery flat; reconstructed
- 10 Feb 2016 – 12 May 2016 (wind): Wind sensor out; Harpenden and Tottenham wind substituted
- 4 Sep 2016 – 17 Sep 2016 (temperature): T/H sensor failed; casa and St Albans data substituted
- 4 Sep 2016 – 30 Sep 2017 (humidity): Humidity read 5-10% low vs Heathrow (failed sensor, then replacement)
- 12 Mar 2017 – 1 Sep 2017 (rain): Rain gauge broken; casa, N16 and Brixton rain substituted
- 22 Sep 2018 – 25 Sep 2018 (all station data): Weather PC died; E2 and N16 data substituted
- 23 Sep 2019 – 24 Sep 2019 (rain): Rain gauge broken
- 16 Aug 2020 – 19 Aug 2020 (rain): Rain gauge blocked; St James backfill
- 1 Sep 2020 – 16 Mar 2021 (wind): Wind sensor under-reading, then Harpenden wind substituted
- 12 Jul 2021 – 14 Jul 2021 (rain): Rain gauge blocked; tips delayed
- 1 Apr 2022 – 23 Feb 2025 (humidity): Humidity drifted 5-7% high vs Heathrow until the sensor died (Feb 2025)
- 15 Sep 2022 – 18 Sep 2022 (all station data): Power cut; logger stuck, then EGLC data
- 15 Apr 2024 – 2 May 2024 (rain): Rain gauge blocked, then broken; Islington rain substituted
- 28 Jun 2024 – 30 Nov 2024 (wind): Wind sensor dead, then weak; Harpenden wind substituted
- 4 Feb 2025 – 23 Feb 2025 (temperature): T/H sensor died; Islington and Potters Bar data substituted
- 1 Nov 2025 – 4 Apr 2026 (sunshine): Webcam sunshine on hold (not yet reviewed)
- 26 Jun 2026 – 28 Jun 2026 (all station data): Station outage; Islington CWOP data filled in
Times are UK clock time (GMT in winter, BST in summer). Profiles are rebuilt nightly, last on 2 Nov 2026 21:59. See also the climate averages.