Climate averages 1991–2020
Helong weather
in September.
A mild, moderately wet month: the 4th warmest and the 8th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a mild month in Helong: daytime highs average 20.9°C and nights cool to about 10.2°C. By daytime temperature it is the 4th warmest of the 12 months.
Expect about 75 mm of rain on roughly 9 days, which makes September a moderately wet month (the 8th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 32 min on an average September day.
The nearest other city in this atlas is Longjing (43 km away). In September its highs average 21.3°C, about as warm as Helong, with 67 mm of rain.
Among the 884 cities listed in China, Helong ranks joint 790th of 884 for the warmest September highs and joint 309th of 884 for the driest September (rainfall, lowest first). The mean September high of those 884 cities is 25.7°C; Helong is 4.7°C cooler than that mean.
From September to October, average highs fall by 7.6°C to 13.3°C, and monthly rainfall falls from 75 mm to 39 mm.
The annual picture
September in context
Monthly precipitation
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Helong climate table
| Month | Average highHigh / low | Average low | Precipitation mm/month | Wet days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | -7.3°C-19.6°C | -19.6°C | 7.7 | 1.7 | 9.49 h |
| February | -3.2°C-16.6°C | -16.6°C | 14 | 3.5 | 10.511 h |
| March | 3.8°C-8.9°C | -8.9°C | 27 | 6.9 | 11.912 h |
| April | 13.0°C0.3°C | 0.3°C | 54 | 9.9 | 13.313 h |
| May | 19.5°C6.8°C | 6.8°C | 100 | 15.4 | 14.615 h |
| June | 23.7°C12.8°C | 12.8°C | 127 | 16.4 | 15.215 h |
| July | 26.2°C17.1°C | 17.1°C | 177 | 17.2 | 15.015 h |
| August | 25.7°C16.9°C | 16.9°C | 160 | 15.8 | 13.914 h |
| September, selected | 20.9°C10.2°C | 10.2°C | 75 | 9.3 | 12.513 h |
| October | 13.3°C2.3°C | 2.3°C | 39 | 7.4 | 11.111 h |
| November | 3.1°C-6.3°C | -6.3°C | 28 | 5.7 | 9.810 h |
| December | -5.2°C-16.2°C | -16.2°C | 11 | 3.4 | 9.19 h |
Precipitation (rain or snow, as water) is the average of the 30 separate monthly totals. A wet day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
September in nearby cities
- Longjing in SeptemberChina · 43 kmHigh 21.3°C · Low 9.9°C · 67 mm rain
- Yanji in SeptemberChina · 57 kmHigh 21.6°C · Low 10.4°C · 66 mm rain
- Tumen in SeptemberChina · 84 kmHigh 21.6°C · Low 11.3°C · 63 mm rain
- Chongjin in SeptemberNorth Korea · 105 kmHigh 20.4°C · Low 14.6°C · 121 mm rain
- Wangqing in SeptemberChina · 106 kmHigh 20.7°C · Low 10.7°C · 60 mm rain
- Ŭndŏk in SeptemberNorth Korea · 110 kmHigh 22.2°C · Low 12.9°C · 89 mm rain
- Dunhua in SeptemberChina · 111 kmHigh 19.5°C · Low 9.3°C · 68 mm rain
- Hunchun in SeptemberChina · 117 kmHigh 21.5°C · Low 10.8°C · 76 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Helong) is explained once on the Helong year overview and on the Sources, method and limits page.