Daily Report for 18th August 2019

Measure	Value (anomaly)	Time	Month cumul.	Record High	Record Low
Minimum Temperature	14.0 °C (-0.1)	23:54	14.7 °C (+0.3)	20.0 °C (+5.9), 2012	11.4 °C (-2.7), 2014
Maximum Temperature	21.5 °C (-0.9)	15:51	22.6 °C (-0.3)	30.0 °C (+7.6), 2012	17.1 °C (-5.3), 2011
Mean Temperature	16.9 °C (-0.5)		18.4 °C (-0.0)	25.0 °C, 2012	13.7 °C, 2011
Minimum Humidity	51%	17:17	55%	72%, 2023	40%, 2012
Maximum Humidity	89%	23:25	90%	95%, 2022	71%, 2015
Mean Humidity	77%		75%	86%, 2023	53%, 2012
Minimum Pressure	1003 hPa	07:18	1009 hPa	1020 hPa, 2018	1003 hPa, 2019
Maximum Pressure	1010 hPa	23:55	1015 hPa	1024 hPa, 2025	1010 hPa, 2010
Mean Pressure	1006 hPa		1012 hPa	1022 hPa, 2025	1006 hPa, 2019
Mean Wind Speed	6.2 mph (+2.2)		5.7 mph (+1.7)	6.3 mph, 2017	2.3 mph, 2024
Maximum Wind Speed	16.1 mph	14:29	14.5 mph	16.1 mph, 2019	8.8 mph, 2024
Maximum Gust	26.5 mph	18:10	23.8 mph	26.5 mph, 2019	13.5 mph, 2024
Mean Wind Direction	n/a		SSW	NW, 2026	NNE, 2011
Rainfall	4.8 mm		36.2 mm (115%)	14.6 mm, 2011	0.0 mm, 2009
Maximum Hourly Rain	2.6 mm	10:54	1.2 mm	9.9 mm, 2017	0.5 mm, 2020
Maximum 10-min Rain	1.3 mm	20:01	0.8 mm	5.9 mm, 2017	0.3 mm, 2021
Maximum Rain Rate	13 mm/h	19:54	9 mm/h	84 mm/h, 2023	0.3 mm/h, 2021
Minimum Dew Point	10.7 °C	17:17	11.7 °C	15.6 °C, 2022	5.6 °C, 2014
Maximum Dew Point	14.2 °C	12:17	15.8 °C	18.6 °C, 2023	10.5 °C, 2014
Mean Dew Point	12.6 °C		13.7 °C	17.2 °C, 2023	8.6 °C, 2014
Measure	Value	Time	Month cumul.	Record High	Record Low
Night Minimum (21-09)	15.0 °C	06:25	14.9 °C	20.0 °C, 2012	11.4 °C, 2014
Day Maximum (09-21)	21.5 °C	15:51	22.6 °C	30.0 °C, 2012	17.1 °C, 2011
Max 10m Temp Rise	0.7 °C	12:17	0.6 °C	0.8 °C, 2017	0.3 °C, 2011
Max 1hr Temp Rise	2.8 °C	12:41	2.2 °C	2.8 °C, 2010	1.0 °C, 2018
Max 1hr Hum Rise	17%	20:17	13%	20%, 2017	4%, 2021
Max 10m Temp Fall	0.9 °C	20:01	0.7 °C	2.9 °C, 2017	0.2 °C, 2015
Max 1hr Temp Fall	2.9 °C	20:35	2.0 °C	4.4 °C, 2017	0.6 °C, 2015
Max 1hr Hum Fall	15%	12:46	11%	15%, 2016	6%, 2015
Max 10m Wind Speed	12.3 mph	16:06	10.9 mph	12.3 mph, 2019	6.1 mph, 2009
Minimum Feels-like	16.3 °C	23:50	17.1 °C	22.9 °C, 2012	11.5 °C, 2014
Maximum Feels-like	23.8 °C	14:19	26.1 °C	34.9 °C, 2012	18.7 °C, 2011
Mean Feels-like	19.5 °C		21.7 °C	28.7 °C, 2012	15.3 °C, 2011
Air-frost Hrs	0 hrs		0 hrs	0 hrs, 2009	0 hrs, 2009
Minimum PM2.5	n/a		0.0 µg/m³	2.7 µg/m³, 2026	0.0 µg/m³, 2009
Maximum PM2.5	n/a		0.0 µg/m³	14.8 µg/m³, 2026	14.8 µg/m³, 2026
Mean PM2.5	n/a		0.0 µg/m³	7.2 µg/m³, 2026	7.2 µg/m³, 2026
Measure	Value (anomaly)		Month cumul.	Record High	Record Low
Temperature Range	7.5 °C (-0.8)		7.9 °C	10.0 °C, 2012	4.9 °C, 2015
Humidity Range	38%		35%	50%, 2010	20%, 2018
Pressure Range	7 hPa		6 hPa	9 hPa, 2023	2 hPa, 2020

Observation	Detail
Sun Hours	5 hrs [38%]
Wet Hours	3 hrs
Cloud Cover	am: Mostly Cloudy pm: Partly Cloudy
Events	None
Comments	am Rn? 20 Sh
Observer Absent?	Yes - observations may be unreliable
Pond Temperature	18.0 °C

Notes: Detailed daily weather report for Hampstead, NW3, London on 18th August 2019. 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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