Daily Report for 18th November 2009

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Measure Value (anomaly) Time Month cumul. Record High Record Low
Minimum Temperature 10.9 °C (+5.8) 01:43 6.9 °C (+1.0) 10.9 °C (+5.8), 2009 -0.1 °C (-5.2), 2019
Maximum Temperature 13.8 °C (+3.4) 16:28 12.1 °C (+1.0) 15.2 °C (+4.8), 2020 7.3 °C (-3.1), 2016
Mean Temperature 12.7 °C (+4.6) 9.4 °C (+1.0) 12.7 °C, 2015 4.7 °C, 2012
Minimum Humidity 73% 17:26 74% 92%, 2013 60%, 2016
Maximum Humidity 85% 13:31 95% 98%, 2010 77%, 2016
Mean Humidity 77% 87% 96%, 2013 70%, 2016
Minimum Pressure 1007 hPa 06:23 996 hPa 1028 hPa, 2021 991 hPa, 2016
Maximum Pressure 1014 hPa 21:06 1006 hPa 1031 hPa, 2021 998 hPa, 2016
Mean Pressure 1010 hPa 1001 hPa 1030 hPa, 2021 994 hPa, 2016
Mean Wind Speed 11.0 mph (+6.4) 5.2 mph (+0.6) 11.0 mph, 2009 1.6 mph, 2012
Maximum Wind Speed 19.6 mph 12.8 mph 22.8 mph, 2015 5.4 mph, 2012
Maximum Gust 27.6 mph 09:21 18.3 mph 37.1 mph, 2015 7.6 mph, 2012
Mean Wind Direction SW
Rainfall trace 69.5 mm (173%) 18.5, 2024
Maximum Hourly Rain n/a 4.1, 2024
Maximum 10-min Rain n/a 1, 2024
Maximum Rain Rate n/a 8, 2010
Minimum Dew Point 7.2 °C 00:06 5.0 °C 7.2 °C, 2009 -1.4 °C, 2019
Maximum Dew Point 10.8 °C 13:55 9.7 °C 13.9 °C, 2023 2.6 °C, 2016
Mean Dew Point 8.8 °C 7.2 °C 11.1 °C, 2023 0.3 °C, 2016
Measure Value Time Month cumul. Record High Record Low
Night Minimum (21-09) 10.9 °C 7.4 °C 11.6 °C, 2020 1.0 °C, 2012
Day Maximum (09-21) 13.8 °C 11.9 °C 15.2 °C, 2020 7.2 °C, 2016
Max 10m Temp Rise 0.2 °C 02:46 0.5 °C 0.6 °C, 2012 0.1 °C, 2013
Max 1hr Temp Rise 0.6 °C 04:16 1.2 °C 1.9 °C, 2012 0.3 °C, 2013
Max 1hr Hum Rise 10% 11:46 6% 11%, 2020 2%, 2013
Max 10m Temp Fall 0.4 °C 11:01 0.5 °C 1.0 °C, 2020 0.2 °C, 2010
Max 1hr Temp Fall 0.5 °C 19:31 1.2 °C 3.0 °C, 2020 0.5 °C, 2009
Max 1hr Hum Fall 9% 15:51 9% 13%, 2018 2%, 2023
Max 10m Wind Speed 16.8 mph 08:00 9.8 mph 16.9 mph, 2015 4.1 mph, 2012
Minimum Feels-like 11.1 °C 01:26 5.7 °C 11.1 °C, 2009 -2.1 °C, 2016
Maximum Feels-like 15.1 °C 13:36 14.1 °C 17.7 °C, 2023 5.8 °C, 2016
Mean Feels-like 13.5 °C 9.5 °C 13.6 °C, 2023 1.8 °C, 2016
Air-frost Hrs 0 hrs 0 hrs 0.2 hrs, 2019 0 hrs, 2009
Measure Value (anomaly) Month cumul. Record High Record Low
Temperature Range 2.9 °C (-2.4) 5.2 °C (+0.0) 8.0 °C (+2.7), 2019 2.9 °C (-2.4), 2009
Humidity Range 12% 22% 29%, 2018 6%, 2013
Pressure Range 7 hPa 10 hPa 18 hPa, 2022 3 hPa, 2011
Measure Value [% of max] Month cumul. Record High Record Low
Sun Hours 0 [0%]42 hrs (81%) [29%] 7.8 [100%], 2018 0 [0%], 2009
Wet Hours 148 hrs (127%) [11%] 12, 2024 0, 2011
Cloud Cover not available
Events None
Comments 10-14 Light patchy Rain
Extra Comments
Issues ALL MONTH: Rainfall data is approximate and 10-min totals & rain rates are unavailable due to 5-min logging, but monthly sum is correct.
Observer Absent? Yes - observations may be unreliable
Pond Temperature (Heath) 0.0 °C
Notes
Detailed daily weather report for Hampstead nw3 in London on 18th November 2009.
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

daygraph daygraph 2 daygraph-wdir

Webcam Summary of Cloud Conditions


Webcam summary not available for this day

Wind rose