2 March 2023

With the northeast monsoon over southern China generally weaker than normal for most of the time in the month, February 2023 was much warmer than usual in Hong Kong. The monthly mean maximum temperature of 22.0 degrees, monthly mean temperature of 18.9 degrees and monthly mean minimum temperature of 16.8 degrees were 2.6 degrees, 1.8 degree and 1.5 degrees above their corresponding normals and respectively the sixth, seventh and one of the eighth highest on record for February. The month was also much drier than usual in Hong Kong. The total rainfall in the month was only 1.6 millimetres, about 4 percent of the normal figure of 38.9 millimetres. The accumulated rainfall recorded in the first two months of the year was 19.8 millimetres, about 72 percent below the normal figure of 71.9 millimetres for the same period.

Under the influence of the northeast monsoon and the subsequent fresh to strong easterly airstream, the weather of Hong Kong was mainly fine on the first two days of the month. Affected by a cloud band covering the coast of Guangdong, local weather turned cloudy with cool mornings on 3 – 5 February. There were also a few rain patches on 4 – 5 February. With the moderation of the easterly airstream, apart from a few light rain patches, the weather became brighter and milder with sunny intervals during the day on 6 – 7 February. Under light wind conditions, the visibility over parts of the territory was also rather low on these two days.

With the setting in of a fresh to strong easterly airstream and a band of clouds covering the coast of Guangdong, the weather of Hong Kong turned mainly cloudy and cooler with a few light rain patches on 8 February. Apart from a few light rain and mist patches in the morning, there were sunny intervals during the day on 9 – 10 February. Under the influence of a humid maritime airstream, it was foggy with a few rain patches on 11 – 13 February. The visibility in some areas once fell below 500 metres on 12 – 13 February. It was also rather warm with sunny periods on the afternoon of 13 February.

Meanwhile, a cold front moved across the coastal areas of Guangdong on the night of 13 February. Under the influence of the associated northeast monsoon, local weather became appreciably cooler on 14 February. There were coastal mist and a few rain patches at first and bright periods during the day on that day. Apart from cloudy interludes on 16 February, it was generally fine and dry with cool mornings on 15 – 17 February. The temperatures at the Observatory fell to a minimum of 13.1 degrees on the morning of 15 February, the lowest of the month.

With the moderation of the northeast monsoon, apart from a few rain patches on the morning of 19 February, the weather was dry and rather warm with sunny periods during the day on 18 – 20 February. The temperatures at the Observatory rose to a maximum of 26.6 degrees on the afternoon of 19 February, the highest of the month and also the warmest Spring Showers on record. Affected by a strong northeast monsoon and the subsequent replenishment, the weather of Hong Kong was generally fine and dry with cool mornings till the end of the month.

There was no tropical cyclone over the South China Sea and the western North Pacific in February 2023.

Sea fog near North Point on 12 February 2023 (Courtesy of Jane Wong)

Warnings and Signals issued in February 2023

Table 1.1   Strong Monsoon Signal

Beginning Time		Ending Time
Day/Month	HKT	Day/Month	HKT
2 / 2	1245	3 / 2	0945
14 / 2	0520	14 / 2	1120
21 / 2	1400	22 / 2	1140
27 / 2	0230	27 / 2	1145

Table 1.2   Fire Danger Warnings

Colour	Beginning Time		Ending Time
	Day/Month	HKT	Day/Month	HKT
Red	15 / 2	0600	15 / 2	2030
Red	16 / 2	0945	16 / 2	2230
Yellow	18 / 2	0600	19 / 2	2130
Red	21 / 2	0930	21 / 2	2030
Red	22 / 2	0600	22 / 2	2130
Red	24 / 2	0630	26 / 2	2245
Red	27 / 2	0600	27 / 2	2000

Table 1.3   Cold Weather Warning

Beginning Time		Ending Time
Day/Month	HKT	Day/Month	HKT
14 / 2	1620	15 / 2	1010

Table 2   Figures and Departures from Normal - February 2023

Meteorological Element	Figure of the Month	Departure from Normal*
Mean Daily Maximum Air Temperature	22.0 degrees C	2.6 degrees above normal
Mean Air Temperature	18.9 degrees C	1.8 degrees above normal
Mean Daily Minimum Air Temperature	16.8 degrees C	1.5 degrees above normal
Mean Dew Point Temperature	13.7 degrees C	0.5 degree above normal
Mean Relative Humidity	73 %	6 % below normal
Mean Cloud Amount	60 %	12 % below normal
Total Rainfall	1.6 mm	37.3 mm below normal
Number of hours of Reduced VisibilityΔ	22 hours	88.1 hours below normal§
Total Bright Sunshine Duration	163.8 hours	62.1 hours above normal
Mean Daily Global Solar Radiation	14.64 Megajoule / square metre	4.4 Megajoule above normal
Total Evaporation	82.8 mm	22.4 mm above normal

Remarks :	All measurements were made at the Hong Kong Observatory except sunshine, solar radiation and evaporation which were recorded at King's Park Meteorological Station and visibility which was observed at the Hong Kong International Airport.
Δ	The visibility readings at the Hong Kong International Airport are based on hourly observations by professional meteorological observers in 2004 and before, and average readings over the 10-minute period before the clock hour of the visibility meter near the middle of the south runway from 2005 onwards. The change of the data source in 2005 is an improvement of the visibility assessment using instrumented observations following the international trend. Before 10 October 2007, the number of hours of reduced visibility at the Hong Kong International Airport in 2005 and thereafter displayed in this web page was based on hourly visibility observations by professional meteorological observers. Since 10 October 2007, the data have been revised using the average visibility readings over the 10-minute period before the clock hour, as recorded by the visibility meter near the middle of the south runway.
*	Departure from 1991 - 2020 climatological normal, except for number of hours of reduced visibility
§	Departure from mean value between 1997 and 2022

Remarks :

Extremely high: above 95th percentile Above normal: between 75th and 95th percentile Normal: between 25th and 75th percentile Below normal: between 5th and 25th percentile Extremely low: below 5th percentile Percentile and 5-day running average values are computed based on the data from 1991 to 2020