Daily Report for 13th March 2021

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Measure Value (anomaly) Time Month cumul. Record High Record Low
Minimum Temperature 4.3 °C (+0.2) 22:03 3.0 °C (-0.8) 10.6 °C (+6.5), 2024 -0.2 °C (-4.3), 2013
Maximum Temperature 9.9 °C (-0.7) 12:26 8.5 °C (-1.7) 16.7 °C (+6.1), 2014 5.8 °C (-4.8), 2013
Mean Temperature 6.8 °C (-0.3) 5.7 °C (-1.2) 12.2 °C, 2023 2.2 °C, 2013
Minimum Humidity 56% 17:22 66% 81%, 2024 37%, 2015
Maximum Humidity 90% 01:14 90% 97%, 2014 76%, 2015
Mean Humidity 74% 80% 88%, 2012 52%, 2015
Minimum Pressure 990 hPa 02:32 1016 hPa 1034 hPa, 2012 987 hPa, 2023
Maximum Pressure 1006 hPa 22:57 1024 hPa 1035 hPa, 2012 997 hPa, 2023
Mean Pressure 997 hPa 1020 hPa 1034 hPa, 2012 991 hPa, 2023
Mean Wind Speed 11.7 mph (+6.5) 5.5 mph (+0.3) 14.2 mph, 2023 1.4 mph, 2014
Maximum Wind Speed 21.7 mph 04:02 13.8 mph 26.7 mph, 2023 6.4 mph, 2014
Maximum Gust 33.1 mph 14:41 20.4 mph 42.6 mph, 2023 8.5 mph, 2014
Mean Wind Direction W
Rainfall 2.4 mm 15.0 mm (92%) 2.4 mm, 2021
Maximum Hourly Rain 1.9 mm 01:13 1.9 mm, 2021
Maximum 10-min Rain 0.9 mm 01:00 0.9 mm, 2021
Maximum Rain Rate 4.8 mm/h 00:54 4.8 mm/h, 2021
Minimum Dew Point -0.2 °C 17:27 0.2 °C 8.6 °C, 2024 -4.3 °C, 2013
Maximum Dew Point 5.7 °C 01:11 4.4 °C 10.9 °C, 2023 -0.3 °C, 2013
Mean Dew Point 2.3 °C 2.3 °C 9.7 °C, 2024 -2.3 °C, 2013
Measure Value Time Month cumul. Record High Record Low
Night Minimum (21-09) * 5.3 °C * 05:54 3.3 °C 11.0 °C, 2024 0.3 °C, 2013
Day Maximum (09-21) 9.9 °C 12:26 8.4 °C 16.7 °C, 2014 5.8 °C, 2013
Max 10m Temp Rise 0.5 °C 11:53 0.4 °C 0.9 °C, 2025 0.2 °C, 2011
Max 1hr Temp Rise 1.4 °C 10:48 1.2 °C 3.5 °C, 2014 0.8 °C, 2011
Max 1hr Hum Rise 12% 18:24 7% 20%, 2013 2%, 2024
Max 10m Temp Fall 0.7 °C 12:43 0.4 °C 2.1 °C, 2025 0.2 °C, 2024
Max 1hr Temp Fall 2.3 °C 18:18 1.3 °C 2.5 °C, 2013 0.8 °C, 2019
Max 1hr Hum Fall 12% 13:44 8% 19%, 2014 3%, 2024
Max 10m Wind Speed 18.2 mph 01:52 10.3 mph 20.9 mph, 2023 4.9 mph, 2012
Minimum Feels-like -0.8 °C 23:00 -0.5 °C 11.4 °C, 2024 -4.1 °C, 2013
Maximum Feels-like 7.9 °C 12:34 8.3 °C 16.7 °C, 2014 3.7 °C, 2013
Mean Feels-like 3.0 °C 3.8 °C 13.1 °C, 2023 -0.5 °C, 2013
Air-frost Hrs 0 hrs 0.2 hrs 0.6 hrs, 2013 0 hrs, 2009
Measure Value (anomaly) Month cumul. Record High Record Low
Temperature Range 5.6 °C (-0.9) 5.5 °C (-0.9) 13.9 °C (+7.4), 2014 2.7 °C (-3.8), 2024
Humidity Range 34% 24% 58%, 2014 11%, 2024
Pressure Range 16 hPa 9 hPa 16 hPa, 2021 1 hPa, 2012
Measure Value [% of max] Month cumul. Record High Record Low
Sun Hours 3 [29%]34 hrs (74%) [25%] 8 [76%], 2014 0 [0%], 2022
Wet Hours 2.5
[Mean rain rate: 1.0 mm/h]		19 hrs (83%) [5.9%] 2.5, 2021 , 2009
Cloud Cover Partly Cloudy
Events None
Comments -02 rn, lunch brief shs
Extra Comments good cb clouds and possible rainbows
Issues None known
Observer Absent? Yes - observations may be unreliable
Pond Temperature @ Hampstead Heath 6.5 °C
Notes
Detailed daily weather report for Hampstead nw3 in London on 13th March 2021.
Times of extremes are computed using the midpoint of the longest continuous period at that extreme value.
Cumulative anomalies are reported according to the expected value for the month-to-date rather than month-end.
Sun hrs are derived based on analysis of webcam observations, but may use data from our closest site, Heathrow, when needed.
Wet hrs are dervied algorithmically from rainfall data, though may be adjusted manually.
Rainfall totals may be manually adjusted after the fact to correct delayed or erroneous data.
Cloud cover and Events are manually reported, often with multi-week delays.
Data is generally reliable and accurate but should always be viewed with some quantity of salt to hand.
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Daily Graph of Conditions

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Webcam Summary of Cloud Conditions

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Wind rose