Daily Report for 12th August 2018

Measure	Value (anomaly)	Time	Month cumul.	Record High	Record Low
Minimum Temperature	16.2 °C (+1.8)	23:51	14.7 °C (+0.2)	21.1 °C (+6.8), 2020	11.9 °C (-2.4), 2019
Maximum Temperature	21.8 °C (-1.0)	11:31	26.1 °C (+3.0)	33.9 °C (+11.1), 2020	18.8 °C (-4.0), 2019
Mean Temperature	18.4 °C (+0.4)		20.5 °C (+1.6)	26.5 °C, 2020	15.2 °C, 2019
Minimum Humidity	55%	12:05	44%	72%, 2021	28%, 2026
Maximum Humidity	90%	23:41	89%	93%, 2024	73%, 2013
Mean Humidity	77%		67%	86%, 2009	53%, 2022
Minimum Pressure	1008 hPa	23:06	1015 hPa	1023 hPa, 2026	1005 hPa, 2014
Maximum Pressure	1018 hPa	00:00	1021 hPa	1026 hPa, 2026	1009 hPa, 2014
Mean Pressure	1012 hPa		1018 hPa	1025 hPa, 2026	1007 hPa, 2014
Mean Wind Speed	5.5 mph (+1.5)		3.5 mph (-0.5)	8.3 mph, 2016	1.7 mph, 2019
Maximum Wind Speed	15.7 mph	12:28	11.6 mph	20.6 mph, 2016	9.1 mph, 2026
Maximum Gust	26.5 mph	12:29	18.6 mph	37.1 mph, 2016	12.8 mph, 2011
Mean Wind Direction	n/a		SSW	NW, 2019	NE, 2015
Rainfall	0.9 mm		24.4 mm (117%)	4.0 mm, 2019	0.0 mm, 2011
Maximum Hourly Rain	0.7 mm	22:52	0.9 mm	3.7 mm, 2019	0.3 mm, 2010
Maximum 10-min Rain	0.4 mm	22:52	0.5 mm	3.3 mm, 2019	0.2 mm, 2015
Maximum Rain Rate	11 mm/h	22:52	14 mm/h	40 mm/h, 2019	0.3 mm/h, 2015
Minimum Dew Point	12.0 °C	12:07	11.0 °C	17.6 °C, 2020	4.2 °C, 2013
Maximum Dew Point	15.6 °C	07:28	16.4 °C	24.2 °C, 2024	11.2 °C, 2014
Mean Dew Point	14.2 °C		13.6 °C	19.7 °C, 2024	7.6 °C, 2013
Measure	Value	Time	Month cumul.	Record High	Record Low
Night Minimum (21-09)	16.7 °C	01:29	14.9 °C	21.1 °C, 2020	12.4 °C, 2014
Day Maximum (09-21)	21.8 °C	11:31	25.9 °C	33.9 °C, 2020	18.8 °C, 2019
Max 10m Temp Rise	0.6 °C	09:53	0.6 °C	0.9 °C, 2013	0.4 °C, 2009
Max 1hr Temp Rise	2.3 °C	10:39	2.8 °C	3.2 °C, 2026	1.2 °C, 2010
Max 1hr Hum Rise	15%	13:06	14%	15%, 2018	4%, 2017
Max 10m Temp Fall	0.5 °C	12:32	0.7 °C	1.1 °C, 2014	0.3 °C, 2015
Max 1hr Temp Fall	1.8 °C	12:59	2.5 °C	2.8 °C, 2016	1.0 °C, 2009
Max 1hr Hum Fall	16%	10:33	15%	16%, 2018	6%, 2009
Max 10m Wind Speed	11.8 mph	12:32	8.6 mph	15.6 mph, 2016	6.3 mph, 2026
Minimum Feels-like	19.9 °C	23:46	17.2 °C	27.2 °C, 2020	13.0 °C, 2019
Maximum Feels-like	24.7 °C	11:06	29.3 °C	44.5 °C, 2024	20.1 °C, 2014
Mean Feels-like	21.9 °C		23.8 °C	33.4 °C, 2020	16.5 °C, 2014
Air-frost Hrs	0 hrs		0 hrs	0 hrs, 2009	0 hrs, 2009
Minimum PM2.5	n/a		0.0 µg/m³	3.4 µg/m³, 2026	0.0 µg/m³, 2009
Maximum PM2.5	n/a		0.0 µg/m³	8.8 µg/m³, 2026	8.8 µg/m³, 2026
Mean PM2.5	n/a		0.0 µg/m³	4.6 µg/m³, 2026	4.6 µg/m³, 2026
Measure	Value (anomaly)		Month cumul.	Record High	Record Low
Temperature Range	5.6 °C (-2.8)		11.4 °C	16.3 °C, 2026	4.9 °C, 2021
Humidity Range	35%		45%	56%, 2026	18%, 2021
Pressure Range	10 hPa		6 hPa	10 hPa, 2018	2 hPa, 2021

Observation	Detail
Sun Hours	0.4 hrs [3%]
Wet Hours	2 hrs
Cloud Cover	am: Overcast with periods of Hazy pm: Overcast
Events	None
Comments	late eve Rn
Observer Absent?	Yes - observations may be unreliable
Pond Temperature	0.0 °C

Notes: Detailed daily weather report for Hampstead, NW3, London on 12th August 2018. 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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