The Weather of January 2025 - A dry and sunny January
Affected by an easterly airstream, the weather of Hong Kong was mainly cloudy on the first two days of the month, with one or two light rain patches on 1 January. Under the influence of the northeast monsoon, it was generally fine on 3 – 9 January apart from a few light rain patches on the night of 4 January and on the morning of 5 January.
With the arrival of an intense winter monsoon on the night of 9 January, the weather was cold on the mornings of the following three days. It was very dry with the relative humidity over the territory staying at 30 percent or below during the day on 12 January. The daily minimum relative humidity of 9 percent at Chek Lap Kok was the second lowest on record for January since the station was established in June 1997. As the monsoon was replaced by an easterly airstream, the weather turned milder gradually on 13 – 15 January. The temperatures at the Observatory rose to a maximum of 22.3 degrees on the afternoon of 15 January, the highest of the month.
Under the influence of a dry northeast monsoon, it was generally fine with cool mornings on 16 – 20 January. Affected by a fresh to strong easterly airstream and a band of clouds covering the coast of Guangdong, local weather became cloudier with a few rain patches in the following three days. With the band of clouds thinning out, it was generally fine on 24 – 25 January.
A cold front moved across the coast of southern China on the morning of 26 January. Locally, it was mainly cloudy with one or two rain patches on that day. With the strengthening of the northerlies, the weather of Hong Kong became cold progressively that night. Under the influence of the associated intense winter monsoon, it turned generally fine and very dry with cold mornings on 27 – 28 January. The temperatures at the Observatory dropped to a minimum of 10.6 degrees on the morning of 27 January, the lowest of the month. The monsoon was gradually replaced by a fresh to strong easterly airstream on 29 January. While it was cloudy at first, the weather turned fine and very dry during the day. With a band of clouds setting in over the coast of Guangdong, the weather turned cloudy on the night of 30 January and there were one or two rain patches on the last day of the month.
There was no tropical cyclone over the South China Sea and the western North Pacific in January 2025.
Details of issuance and cancellation of various warnings/signals in the month are summarised in Tables 1.1 to 1.4. Monthly meteorological figures and departures from normal for January are tabulated in Table 2.
Warnings and Signals issued in January 2025
Beginning Time | Ending Time | ||
---|---|---|---|
Day/Month | HKT | Day/Month | HKT |
26 / 1 | 1530 | 27 / 1 | 1145 |
Colour | Beginning Time | Ending Time | ||
---|---|---|---|---|
Day/Month | HKT | Day/Month | HKT | |
Red | 3 / 1 | 0600 | 3 / 1 | 2315 |
Yellow | 4 / 1 | 0600 | 4 / 1 | 2130 |
Red | 5 / 1 | 0600 | 5 / 1 | 1945 |
Red | 6 / 1 | 0600 | 6 / 1 | 2330 |
Red | 9 / 1 | 0600 | 13 / 1 | 2345 |
Red | 15 / 1 | 0600 | 18 / 1 | 2330 |
Red | 19 / 1 | 0600 | 19 / 1 | 2245 |
Red | 20 / 1 | 0600 | 20 / 1 | 2310 |
Red | 21 / 1 | 0600 | 21 / 1 | 1645 |
Red | 27 / 1 | 0600 | 30 / 1 | 0600 |
Yellow | 30 / 1 | 0600 | 30 / 1 | 2145 |
Yellow | 31 / 1 | 0600 | 31 / 1 | 1800 |
Beginning Time | Ending Time | ||
---|---|---|---|
Day/Month | HKT | Day/Month | HKT |
10 / 1 | 1630 | 11 / 1 | 0745 |
11 / 1 | 1630 | 12 / 1 | 0745 |
Beginning Time | Ending Time | ||
---|---|---|---|
Day/Month | HKT | Day/Month | HKT |
9 / 1 | 1620 | 13 / 1 | 1015 |
26 / 1 | 1100 | 29 / 1 | 0900 |
Meteorological Element | Figure of the Month | Departure from Normal* |
---|---|---|
Mean Daily Maximum Air Temperature | 19.8 degrees C | 1.1 degrees above normal |
Mean Air Temperature | 17.1 degrees C | 0.6 degrees above normal |
Mean Daily Minimum Air Temperature | 15.0 degrees C | 0.4 degrees above normal |
Mean Dew Point Temperature | 8.5 degrees C | 3.2 degrees below normal |
Mean Relative Humidity | 59 % | 15 % below normal |
Mean Cloud Amount | 44 % | 18 % below normal |
Total Rainfall | 4.2 mm | 29.0 mm below normal |
Number of hours of Reduced VisibilityΔ | 2 hours | 190.3 hours below normal§ |
Total Bright Sunshine Duration | 222.3 hours | 76.5 hours above normal |
Mean Daily Global Solar Radiation | 14.82 Megajoule / square metre | 4.27 Megajoule above normal |
Total Evaporation | 101.3 mm | 32.2 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. |
* Departure from 1991 - 2020 climatological normal, except for number of hours of reduced visibility |
|
§ Departure from mean value between 1997 and 2024 |


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 |
Extract of Meteorological Observations in Hong Kong for January 2025