Weather in Hennef (Sieg)

Forecast: MOSMIX (DWD-Statistik über ICON + ECMWF) · Run 10.08. 23:00 Uhr · Station SIEGBURG (6,4 km from the centre) · own station correction −0,2 °C (from our station comparison). We show where our data comes from – and how often we get it wrong. Measured against official stations, we were recently off by ±0,9 °C here (up to 24 h), rain forecast 98 % correct.
Today: settled weather – historically easy to forecast.
We beat the "same as yesterday" rule of thumb by 56 %.

Now · as of 06:00

14°klar

Later today

High · 18:00 Uhr26° Low14°

6 km/h aus NW 16 % 78 % 1024 hPa Rain last 24 h 0,0 mm (measured, as of 05:00) 06:13 20:59 new moon

Rain Radar

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The next few days

Day	Min	Max	Rain	Risk	Sun
Di, 11.08.	14°	26°	0,0 mm	3 %	13,3 h	06:13	20:59
Mi, 12.08.	12°	30° 18:00	0,0 mm	1 %	13,4 h	06:15	20:57
Do, 13.08.	15°	34° 17:00	0,0 mm	2 %	13,4 h	06:16	20:55
Fr, 14.08.	19°	35° 16:00	0,0 mm	2 %	12,6 h	06:18	20:53
Sa, 15.08.	19°	29° 16:00	0,0 mm	4 %	7,4 h	06:19	20:51
So, 16.08.	18°	25° 15:00	0,0 mm	10 %	5,8 h	06:21	20:49
Mo, 17.08.	16°	24° 17:00	4,3 mm	19 %	5,9 h	06:22	20:47
Di, 18.08.	16°	23° 15:00	7,0 mm	23 %	4,5 h	06:24	20:45
Mi, 19.08.	15°	22° 16:00	5,8 mm	19 %	5,0 h	06:25	20:43
Do, 20.08.	14°	23° 19:00	0,0 mm	16 %	6,2 h	06:27	20:41

Outlook: the next few weeks

A genuine day-by-day forecast only reaches about 10 days out – anything beyond that is statistics, not a forecast. That's why we don't show a 30- or 90-day outlook. What can be honestly stated is the long-term normal: in Hennef (Sieg) the average temperature in August is 18,5 °C, in September it's 14,7 °C (1991-2020 climate mean for the local climate station, see below). We show openly how often our forecast actually holds up.

How reliable is the forecast?

How our forecast daily high has shifted across recent runs. Flat line = the forecast is holding, jittery = still shifting.

Di, 11.08.26° stabil (±0,6 °C über 12 Läufe)

Mi, 12.08.30° wackelt noch (±0,8 °C über 12 Läufe)

Do, 13.08.34° stabil (±0,8 °C über 12 Läufe)

Fr, 14.08.35° wackelt noch (±1,3 °C über 12 Läufe)

Today at a glanceDi, 11.08.

Garden no frost

Low of 8,6 °C in 48 h, 0,0 mm rain in 24 h. Spray/watering window: 06:00 to 05:00 (48 h) – dry, calm, stays dry afterwards. Product-dependent – check the label.

Outdoors dry

06:00 to 05:00 (48 h) · gusts up to 26 km/h.

Pollen Mugwort: moderate to high load

Also Grasses low load.

Region Rhein.-Westfäl. Tiefland · As of 10.08., 11:00 Uhr · DWD pollen forecast

Balcony solar: today ≈ 4,43 kWh per kWp, tomorrow 4,70 kWh · Best 2 h for high loads today: 14:00 to 15:00 (south, vertical) – adjust to your orientation in the app.

Climate in Hennef (Sieg) (1991-2020)

The warmest month in Hennef (Sieg) is Juli (avg 18,9 °C), the coldest is Januar (avg 2,7 °C). The most rain falls in Juli (avg 91,2 mm), the least in April (avg 47,0 mm). The sunniest month is Juli (avg 213,0 h).

Annual mean 10,5 °C, 834 mm precipitation, 1624 hours of sunshine, 63 frost days. Weather station Königswinter-Heiderhof (7,6 km away).

Record on 11.08.: 34,0 °C (1998), coldest value 4,1 °C (2016), highest rainfall 23,7 mm (2020) – series since 1937