Daily Report for 17th March 2012

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Measure Value (anomaly) Time Month cumul. Record High Record Low
Minimum Temperature 7.2 °C (+2.7) 23:48 5.1 °C (+1.1) 10.7 °C (+6.2), 2023 -1.7 °C (-6.2), 2018
Maximum Temperature 10.8 °C (-0.2) 14:59 11.6 °C (+1.2) 15.4 °C (+4.4), 2009 7.1 °C (-3.9), 2018
Mean Temperature 9.1 °C (+1.2) 8.2 °C (+1.1) 12.1 °C, 2024 0.5 °C, 2018
Minimum Humidity 76% 00:03 63% 79%, 2024 43%, 2016
Maximum Humidity 89% 12:00 90% 98%, 2011 78%, 2017
Mean Humidity 84% 78% 90%, 2024 65%, 2010
Minimum Pressure 1011 hPa 17:02 1023 hPa 1032 hPa, 2021 987 hPa, 2013
Maximum Pressure 1015 hPa 01:05 1029 hPa 1040 hPa, 2022 993 hPa, 2013
Mean Pressure 1013 hPa 1026 hPa 1034 hPa, 2009 990 hPa, 2013
Mean Wind Speed 5.1 mph (-0.1) 4.7 mph (-0.5) 10.9 mph, 2018 1.9 mph, 2009
Maximum Wind Speed 11.4 mph 11.4 mph 21.2 mph, 2018 7.8 mph, 2011
Maximum Gust 16.1 mph 11:02 16.5 mph 32.3 mph, 2018 10.7 mph, 2011
Mean Wind Direction SW
Rainfall 4.8 mm 21.6 mm (101%) 5.3 mm, 2023
Maximum Hourly Rain 2.6 mm 17:39 2.6 mm, 2012
Maximum 10-min Rain 1.5 mm 17:17 1.5 mm, 2012
Maximum Rain Rate 15 mm/h 17:18 15 mm/h, 2012
Minimum Dew Point 4.7 °C 00:45 1.6 °C 9.1 °C, 2023 -4.1 °C, 2018
Maximum Dew Point 8.6 °C 12:49 6.8 °C 12.2 °C, 2024 3.5 °C, 2025
Mean Dew Point 6.6 °C 4.4 °C 10.4 °C, 2024 -1.5 °C, 2018
Measure Value Time Month cumul. Record High Record Low
Night Minimum (21-09) * 7.9 °C * 03:15 5.6 °C 11.2 °C, 2023 -0.3 °C, 2018
Day Maximum (09-21) 10.8 °C 14:58 11.6 °C 15.4 °C, 2009 0.1 °C, 2018
Max 10m Temp Rise 0.2 °C 09:40 0.4 °C 1.2 °C, 2009 0.1 °C, 2018
Max 1hr Temp Rise 0.7 °C 09:51 1.7 °C 3.1 °C, 2009 0.4 °C, 2018
Max 1hr Hum Rise 6% 18:12 6% 28%, 2019 3%, 2020
Max 10m Temp Fall 0.5 °C 17:14 0.5 °C 2.3 °C, 2019 0.3 °C, 2015
Max 1hr Temp Fall 1.2 °C 17:27 1.7 °C 4.2 °C, 2019 0.9 °C, 2020
Max 1hr Hum Fall 4% 14:30 10% 22%, 2016 4%, 2012
Max 10m Wind Speed 6.9 mph 11:06 8.0 mph 16.7 mph, 2018 5.2 mph, 2011
Minimum Feels-like 5.1 °C 03:08 2.6 °C 11.7 °C, 2023 -9.2 °C, 2018
Maximum Feels-like 11.3 °C 14:36 11.7 °C 17.0 °C, 2024 4.0 °C, 2018
Mean Feels-like 8.2 °C 7.0 °C 13.5 °C, 2024 -5.5 °C, 2018
Air-frost Hrs 0 hrs 0 hrs 15 hrs, 2018 0 hrs, 2009
Measure Value (anomaly) Month cumul. Record High Record Low
Temperature Range 3.6 °C (-2.9) 6.5 °C (+0.1) 10.4 °C (+3.9), 2022 3.3 °C (-3.2), 2023
Humidity Range 13% 27% 49%, 2016 13%, 2012
Pressure Range 4 hPa 6 hPa 18 hPa, 2019 2 hPa, 2018
Measure Value [% of max] Month cumul. Record High Record Low
Sun Hours 0 [0%]62 hrs (103%) [35%] 10 [93%], 2022 0 [0%], 2012
Wet Hours 6
[Mean rain rate: 0.8 mm/h]		26 hrs (90%) [6.4%] 12, 2018 , 2009
Cloud Cover Overcast
Events None
Comments 08, 10-13 Slight-Light broken Rain; 16,17 Heavy Showers; 22- Light Rain
Extra Comments
Issues None known
Observer Absent? Yes - observations may be unreliable
Pond Temperature @ Hampstead Heath 0.0 °C
Notes
Detailed daily weather report for Hampstead nw3 in London on 17th March 2012.
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.
View monthly summary

Daily Graph of Conditions

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Webcam Summary of Cloud Conditions

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Wind rose