Daily Report for 17th August 2020

Measure	Value (anomaly)	Time	Month cumul.	Record High	Record Low
Minimum Temperature	15.1 °C (+1.0)	02:58	16.7 °C (+2.3)	18.1 °C (+4.0), 2012	10.8 °C (-3.3), 2018
Maximum Temperature	23.2 °C (+0.8)	15:47	27.3 °C (+4.4)	27.6 °C (+5.2), 2012	18.2 °C (-4.2), 2021
Mean Temperature	18.2 °C (+0.9)		21.7 °C (+3.4)	22.2 °C, 2012	15.4 °C, 2021
Minimum Humidity	62%	15:56	50%	76%, 2021	33%, 2012
Maximum Humidity	98%	07:27	88%	98%, 2020	76%, 2012
Mean Humidity	85%		71%	90%, 2022	58%, 2012
Minimum Pressure	1008 hPa	16:09	1014 hPa	1024 hPa, 2025	1004 hPa, 2019
Maximum Pressure	1010 hPa	00:18	1017 hPa	1028 hPa, 2025	1006 hPa, 2019
Mean Pressure	1009 hPa		1016 hPa	1026 hPa, 2025	1005 hPa, 2019
Mean Wind Speed	2.2 mph (-1.8)		3.5 mph (-0.5)	7.6 mph, 2014	1.1 mph, 2024
Maximum Wind Speed	14.2 mph	16:24	11.6 mph	17.6 mph, 2014	6.6 mph, 2024
Maximum Gust	23.0 mph	16:27	17.9 mph	26.8 mph, 2013	11.4 mph, 2024
Mean Wind Direction	n/a		SSE	N, 2015	NNE, 2011
Rainfall	1.7 mm		25.2 mm (85%)	35.8 mm, 2022	0.0 mm, 2009
Maximum Hourly Rain	1.2 mm	16:55	1.0 mm	23.1 mm, 2022	0.2 mm, 2013
Maximum 10-min Rain	0.8 mm	16:33	0.4 mm	9.9 mm, 2022	0.2 mm, 2013
Maximum Rain Rate	10 mm/h	16:31	9 mm/h	90 mm/h, 2022	1.1 mm/h, 2011
Minimum Dew Point	14.1 °C	02:55	13.5 °C	15.4 °C, 2022	4.1 °C, 2014
Maximum Dew Point	17.4 °C	17:43	18.1 °C	19.2 °C, 2022	11.3 °C, 2015
Mean Dew Point	15.6 °C		15.8 °C	16.9 °C, 2022	8.0 °C, 2015
Measure	Value	Time	Month cumul.	Record High	Record Low
Night Minimum (21-09)	15.1 °C	02:55	17.0 °C	18.1 °C, 2012	10.8 °C, 2018
Day Maximum (09-21)	23.2 °C	15:48	27.3 °C	27.6 °C, 2012	18.2 °C, 2021
Max 10m Temp Rise	0.7 °C	07:29	0.7 °C	1.0 °C, 2009	0.3 °C, 2010
Max 1hr Temp Rise	2.2 °C	08:06	2.7 °C	3.2 °C, 2025	0.9 °C, 2010
Max 1hr Hum Rise	19%	17:26	10%	22%, 2022	3%, 2015
Max 10m Temp Fall	1.4 °C	16:33	0.7 °C	1.8 °C, 2022	0.3 °C, 2010
Max 1hr Temp Fall	3.3 °C	16:53	2.2 °C	5.0 °C, 2022	0.7 °C, 2021
Max 1hr Hum Fall	11%	14:29	11%	27%, 2014	4%, 2010
Max 10m Wind Speed	10.7 mph	16:30	8.2 mph	13.1 mph, 2014	4.4 mph, 2024
Minimum Feels-like	18.5 °C	02:44	20.3 °C	20.6 °C, 2012	11.8 °C, 2018
Maximum Feels-like	27.8 °C	15:41	32.5 °C	30.9 °C, 2022	20.6 °C, 2015
Mean Feels-like	22.6 °C		26.4 °C	25.0 °C, 2012	17.2 °C, 2015
Air-frost Hrs	0 hrs		0 hrs	0 hrs, 2009	0 hrs, 2009
Minimum PM2.5	n/a		0.0 µg/m³	0.0 µg/m³, 2009	0.0 µg/m³, 2009
Maximum PM2.5	n/a		0.0 µg/m³	n/a	n/a
Mean PM2.5	n/a		0.0 µg/m³	n/a	n/a
Measure	Value (anomaly)		Month cumul.	Record High	Record Low
Temperature Range	8.1 °C (-0.2)		10.6 °C	14.1 °C, 2025	5.2 °C, 2010
Humidity Range	36%		38%	49%, 2016	13%, 2021
Pressure Range	2 hPa		3 hPa	10 hPa, 2013	2 hPa, 2011

Observation	Detail
Sun Hours	2.5 hrs [19%]
Wet Hours	1.5 hrs
Cloud Cover	Mostly Cloudy with periods of Partly Cloudy
Events	Thunder
Comments	13? 1630? 1830 Shs? probs w thunder
Observer Absent?	Yes - observations may be unreliable
Pond Temperature	22.0 °C

Notes: Detailed daily weather report for Hampstead, NW3, London on 17th August 2020. Times of extremes use the midpoint of the longest continuous period at that value. Cumulative anomalies are relative to the expected value for the month-to-date. Sun and wet hours are derived from webcam/rainfall analysis and may be adjusted. Data should be viewed with appropriate caution.

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Daily Graph of Conditions

Wind direction

Air pollution

Wind rose

Webcam Summary of Cloud Conditions

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