Daily Report for 25th December 2009

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Measure Value (anomaly) Time Month cumul. Record High Record Low
Minimum Temperature 1.5 °C (-1.9) 08:26 1.6 °C (-2.1) 10.2 °C (+6.8), 2023 -2.8 °C (-6.2), 2010
Maximum Temperature 5.2 °C (-2.5) 23:56 6.0 °C (-2.2) 14.5 °C (+6.8), 2015 -0.2 °C (-8.0), 2010
Mean Temperature 2.4 °C (-2.2) 3.8 °C (-2.1) 12.1 °C, 2023 -1.5 °C, 2010
Minimum Humidity 93% 14:12 83% 93%, 2009 67%, 2014
Maximum Humidity 98% 12:00 97% 98%, 2009 81%, 2016
Mean Humidity 97% 92% 97%, 2009 78%, 2014
Minimum Pressure 988 hPa 00:53 1003 hPa 1033 hPa, 2018 980 hPa, 2013
Maximum Pressure 1003 hPa 20:08 1011 hPa 1036 hPa, 2018 988 hPa, 2013
Mean Pressure 996 hPa 1007 hPa 1035 hPa, 2018 984 hPa, 2013
Mean Wind Speed 4.7 mph (-0.4) 4.3 mph (-0.8) 10.9 mph, 2017 0.6 mph, 2018
Maximum Wind Speed 10.9 mph 10.7 mph 25.2 mph, 2017 5.4 mph, 2018
Maximum Gust 15.4 mph 12:47 15.9 mph 43.8 mph, 2017 8.1 mph, 2018
Mean Wind Direction W
Rainfall trace 56.9 mm (124%) 12.6, 2012
Maximum Hourly Rain n/a 4, 2017
Maximum 10-min Rain n/a 1.7, 2012
Maximum Rain Rate n/a 26, 2017
Minimum Dew Point 1.2 °C 12:50 0.1 °C 8.5 °C, 2023 -4.8 °C, 2010
Maximum Dew Point 4.9 °C 23:56 5.2 °C 12.4 °C, 2015 -1.7 °C, 2010
Mean Dew Point 2.0 °C 2.6 °C 10.7 °C, 2023 -2.9 °C, 2010
Measure Value Time Month cumul. Record High Record Low
Night Minimum (21-09) 1.5 °C 2.3 °C 11.8 °C, 2023 -2.4 °C, 2010
Day Maximum (09-21) 5.2 °C 5.8 °C 14.3 °C, 2015 -0.7 °C, 2010
Max 10m Temp Rise 0.4 °C 12:44 0.4 °C 0.8 °C, 2013 0.1 °C, 2011
Max 1hr Temp Rise 1.1 °C 22:00 1.0 °C 1.8 °C, 2013 0.1 °C, 2021
Max 1hr Hum Rise 2% 17:49 4% 7%, 2017 1%, 2021
Max 10m Temp Fall 0.2 °C 13:17 0.4 °C 0.9 °C, 2017 0.2 °C, 2009
Max 1hr Temp Fall 0.6 °C 17:05 0.9 °C 3.4 °C, 2017 0.4 °C, 2015
Max 1hr Hum Fall 4% 13:24 5% 10%, 2014 2%, 2010
Max 10m Wind Speed 7.5 mph 13:27 7.7 mph 19.3 mph, 2017 3.6 mph, 2018
Minimum Feels-like -2.5 °C 10:46 -1.7 °C 10.8 °C, 2023 -6.6 °C, 2010
Maximum Feels-like 4.7 °C 23:06 6.4 °C 17.0 °C, 2015 -0.4 °C, 2010
Mean Feels-like 0.0 °C 2.6 °C 13.7 °C, 2023 -3.3 °C, 2010
Air-frost Hrs 0 hrs 4 hrs 24 hrs, 2010 0 hrs, 2009
Measure Value (anomaly) Month cumul. Record High Record Low
Temperature Range 3.7 °C (-0.7) 4.5 °C (-0.1) 8.6 °C (+4.2), 2015 2.0 °C (-2.4), 2022
Humidity Range 5% 14% 20%, 2015 5%, 2009
Pressure Range 15 hPa 8 hPa 24 hPa, 2017 3 hPa, 2016
Measure Value [% of max] Month cumul. Record High Record Low
Sun Hours 2 [29%]67 hrs (127%) [38%] 7 [100%], 2019 0 [0%], 2010
Wet Hours 268 hrs (136%) [11%] 6, 2012 0, 2010
Cloud Cover not available
Events None
Comments 03-05 SLight Rain/Drizzle
Extra Comments 24th - 25th: Patchy Lying Snow remains; 22nd-25th: RHeavy at 98% from 20z on 22nd to 12z on 25th (64 hrs)
Issues None known
Observer Absent? Yes - observations may be unreliable
Pond Temperature (Heath) 0.0 °C
Notes
Detailed daily weather report for Hampstead nw3 in London on 25th December 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