Big Bend National Park forecast › Weekend planner

Eight-week planning horizon

Choose your observing weekend

Big Bend National Park · ranked by total moonless dark hours across Friday and Saturday. Seasonal history is context, not the chance of clear weather on those dates.

Natural-dark sky

Site darkness stays separate from the weather and the scheduling order.

21.9–21.9 mag/arcsec²

Next seven nights in detail · Moonless calendar · Milky Way timing

Choose a planet and find its observing times →

Moonless time rank 1

6 Nov – 7 Nov

20.7h moonless / 20.7h astronomical darkness across both nights

November seasonal context
17.9 usable nights/month on average · 2005–2024. Historical regional cloud and darkness, not this weekend’s weather odds.

Night-by-night timing & conditions

Friday

10.3h moonless · Moon 4% lit
Longest moonless stretch: 19:40–06:00

Weather not available for this night. Geometry only; recheck nearer departure.

Saturday

10.3h moonless · Moon 1% lit
Longest moonless stretch: 19:40–06:00

Weather not available for this night. Geometry only; recheck nearer departure.

Moonless time rank 2

4 Dec – 5 Dec

19.7h moonless / 22.0h astronomical darkness across both nights

December seasonal context
13.3 usable nights/month on average · 2005–2024. Historical regional cloud and darkness, not this weekend’s weather odds.

Night-by-night timing & conditions

Friday

9.3h moonless · Moon 13% lit
Longest moonless stretch: 19:20–04:40

Weather not available for this night. Geometry only; recheck nearer departure.

Saturday

10.3h moonless · Moon 7% lit
Longest moonless stretch: 19:20–05:40

Weather not available for this night. Geometry only; recheck nearer departure.

Moonless time rank 3

13 Nov – 14 Nov

15.7h moonless / 20.7h astronomical darkness across both nights

November seasonal context
17.9 usable nights/month on average · 2005–2024. Historical regional cloud and darkness, not this weekend’s weather odds.

Night-by-night timing & conditions

Friday

8.3h moonless · Moon 22% lit
Longest moonless stretch: 21:40–06:00

Weather not available for this night. Geometry only; recheck nearer departure.

Saturday

7.3h moonless · Moon 30% lit
Longest moonless stretch: 22:40–06:00

Weather not available for this night. Geometry only; recheck nearer departure.

Moonless time rank 4

16 Oct – 17 Oct

12.3h moonless / 19.3h astronomical darkness across both nights

October seasonal context
19.1 usable nights/month on average · 2005–2024. Historical regional cloud and darkness, not this weekend’s weather odds.

Night-by-night timing & conditions

Friday

6.7h moonless · Moon 37% lit
Longest moonless stretch: 00:00–06:40

Forecast cloud range: 82–82% at 1 available dark-time samples. Not full-night coverage or a probability.

Saturday

5.7h moonless · Moon 46% lit
Longest moonless stretch: 01:00–06:40

Weather not available for this night. Geometry only; recheck nearer departure.

Moonless time rank 5

30 Oct – 31 Oct

6.7h moonless / 20.7h astronomical darkness across both nights

October seasonal context
19.1 usable nights/month on average · 2005–2024. Historical regional cloud and darkness, not this weekend’s weather odds.

Night-by-night timing & conditions

Friday

2.7h moonless · Moon 70% lit
Longest moonless stretch: 20:40–23:20

Weather not available for this night. Geometry only; recheck nearer departure.

Saturday

4.0h moonless · Moon 59% lit
Longest moonless stretch: 20:40–00:40

Weather not available for this night. Geometry only; recheck nearer departure.

Moonless time rank 6

27 Nov – 28 Nov

5.0h moonless / 22.0h astronomical darkness across both nights

November seasonal context
17.9 usable nights/month on average · 2005–2024. Historical regional cloud and darkness, not this weekend’s weather odds.

Night-by-night timing & conditions

Friday

2.0h moonless · Moon 83% lit
Longest moonless stretch: 19:20–21:20

Weather not available for this night. Geometry only; recheck nearer departure.

Saturday

3.0h moonless · Moon 73% lit
Longest moonless stretch: 19:20–22:20

Weather not available for this night. Geometry only; recheck nearer departure.

Moonless time rank 7

20 Nov – 21 Nov

2.3h moonless / 21.3h astronomical darkness across both nights

November seasonal context
17.9 usable nights/month on average · 2005–2024. Historical regional cloud and darkness, not this weekend’s weather odds.

Night-by-night timing & conditions

Friday

1.7h moonless · Moon 86% lit
Longest moonless stretch: 04:20–06:00

Weather not available for this night. Geometry only; recheck nearer departure.

Saturday

0.7h moonless · Moon 92% lit
Longest moonless stretch: 05:20–06:00

Weather not available for this night. Geometry only; recheck nearer departure.

Moonless time rank 8

23 Oct – 24 Oct

0.3h moonless / 20.7h astronomical darkness across both nights

October seasonal context
19.1 usable nights/month on average · 2005–2024. Historical regional cloud and darkness, not this weekend’s weather odds.

Night-by-night timing & conditions

Friday

0.3h moonless · Moon 95% lit
Longest moonless stretch: 06:40–07:00

Weather not available for this night. Geometry only; recheck nearer departure.

Saturday

0.0h moonless · Moon 99% lit
No moonless dark window

Weather not available for this night. Geometry only; recheck nearer departure.

How to use this planner

Choose a weekend with enough moonless time, then check the weather and target outlook before travelling. Times use America/Chicago and approximately 20-minute geometry samples. Friday and Saturday are ranked together; hours need not form one continuous window.

The regional NASA climate baseline counts nights with at least three hours of astronomical darkness and mean nighttime cloud at or below 30%. It does not measure telescope seeing or guarantee clear skies. No weather probabilities are inferred from monthly averages. Longer-lead forecasts have coarser sampling.

Full seasonal history and definitions →