Next open dayWed 12 Aug3,454 mcog railway

Jungfraujoch

PEAK89/100

Medium confidence

Conditions line up tomorrow. Best window 09:00–12:00 — go.

Live reading · 17:00 UTC

Instrument reading

Best time tomorrow

09:00–12:0089/100

Evidence for the window

The verdict above is for tomorrow — these are tomorrow's hours, the ones the engine actually scored, with the recommended window lit below.

Rows: local time · temp °C · wind km/h · precip chance % · cloud base m

Cloud base over tomorrow's hours (Wed 12 Aug), 05:00–22:00 local time, against the 3,454 m summit; 10 of 18 hours are clear above it.
Local time	Operating	Temperature (°C)	Wind (km/h)	Precipitation chance (%)	Cloud base (m)	In recommended window
05:00	closed	4	11	0	clear above the summit	no
06:00	closed	4	9	0	clear above the summit	no
07:00	closed	4	7	0	clear above the summit	no
08:00	closed	4	6	0	clear above the summit	no
09:00	open	4	12	0	clear above the summit	yes
10:00	open	4	11	0	clear above the summit	yes
11:00	open	4	7	0	clear above the summit	yes
12:00	open	5	4	0	clear above the summit	no
13:00	open	6	1	0	clear above the summit	no
14:00	open	6	4	0	3620 m	no
15:00	open	6	7	0	3500 m	no
16:00	open	6	9	0	3480 m	no
17:00	open	6	12	14	3420 m	no
18:00	open	5	16	38	3420 m	no
19:00	closed	5	3	48	3920 m	no
20:00	closed	5	5	14	not reported	no
21:00	closed	5	5	0	not reported	no
22:00	closed	5	9	0	clear above the summit	no

The signature reading

The question a forecast percentage cannot answer: is the viewpoint above the cloud, or inside it, right now?

The verdict above is for the next day — this reading is what the sky looks like right now, not then.

Cloud base is around 4420 m, above the 3,454 m viewpoint. The air at the top should be clear, under an overcast sky.

The reasoning, audited

5-day shape