Key Weather Forecasts for Night Photography
When planning a night photography or astrophotography shoot, the weather is a critical factor. It’s not just the obvious things such as the absence of rain and clouds, but many other factors that conspire to make great conditions, or not.
When planning a night photography or astrophotography shoot, the weather is a critical factor. It’s not just the obvious things such as the absence of rain and clouds, but many other factors that conspire to make great conditions, or not.
In this article, we’ll review the primary weather and atmospheric conditions forecasts that you should look for before heading out.
But first of all, what’s the plan?
The Plan: Milky Way over Bear Lake
Annaka, Alice, and I decided we wanted to head up to Bear Lake in Rocky Mountain National Park. The lake lies at around 9,600 feet above sea level. There’s a trail you follow around the entire lake - it’s flat, easy and right next to parking. As a result, it’s overrun during the days in peak season, and a timed entry permit is required to get there. But at night, not so much - you can drive right up year round after 6pm.
From the north side of the a lake, there’s a view to the south that encompasses Longs Peak to the left and the rising terrain of Otis Peak, Thatchtop, and Taylor Peak, amongst others, to the right. You can shoot over the water and get the Galactic Center right in the middle of the frame just above the mountains on a July evening after dark.
Here’s what we were aiming for, shown in TPE 3D:
The Moon is only a couple of days old and will have set in the west some time before the end of twilight, giving us a truly dark night to look forward to.
To get the shot, we’d need unclouded skies, and ideally a few more things to line up. But what?
Key Weather and Atmosphere Variables to Check
Our weather check shortlist includes:
- Multi-level Clouds
- Astronomical Transparency
- Astronomical Seeing
- Total Column Smoke
- Near Ground Smoke
- Visibility
- Wind Gusts
We weren’t too worried about temperature or dew point depression: it’s regularly warm and dry up there at this time of year as long as there’s no storm system moving through.
We used Photo WX, our weather service for photographers, to check out all the key forecasts. Here’s how it lined up as of Saturday morning.
Multi-Level Clouds
Multi-level cloud is a highly efficient way for photographers to assess cloud cover and its potential impact on shot plans. Here, we see some mid-level cloud shown in magenta, but it’s way off to the east of our location (red map pin) and not in our line of sight. There are some small areas of high cloud forecast, but they’re way off to the southwest and again, shouldn’t affect us:
This forecast is from the HRRR forecast, a high resolution hourly model that covers much of North America.
Astronomical Transparency
Next, we checked astronomical transparency, using the new 10km forecast from the Canadian RDPS model. The greater the transparency, the more brilliant the night sky will appear. It accounts for clouds, but assuming clear skies - which we expect already - transparency shows how humidity and moisture in the atmospheric column will affect what you can see.
The clearer areas in this forecast show better transparency (on a 0-5 scale, where 5 is best):
Transparency was looking great (4).
Astronomical Seeing
Astronomical Seeing forecasts tell you how much or little scintillation you can expect to see in the stars. When there is too much wind shear between layers of the atmosphere, the effect is to make the stars shimmer or twinkle - that can look nice, but it’s not what you want as a photographer. Again, the clearer the map, the better the forecast seeing, on a 0-5 scale, where 5 is best:
So, not great, but certainly not terrible either. The area just east of Denver looks good - but then the transparency is not at all good there (not to mention light pollution). You can evaluate both Seeing and Transparency together on the special combined forecast map in Photo WX:
Again, light areas are better.
Total Column Smoke
It’s important to be aware that the dedicated Seeing and Transparency forecasts from Environment Canada do not account for the effects of wildfire smoke. Therefore it’s important to check a smoke forecast independently.
Total Column Smoke from the HRRR model shows the density of smoke particles through the entire atmospheric column. You want it to look pretty much clear if you’re going to try night or astrophotography:
You can see that our location (red map pin) is on the edge of some mild smoke, but with much worse approaching from the west. Check out the scale on the map - the light blue colors show you there’s something there, but it’s really very little. Not too much to be concerned about.
Near Ground Smoke
Sometimes, if there’s a nearby fire, or an atmospheric inversion, you can end up with a lot more near ground smoke than smoke aloft. As near ground smoke affects the air quality that we breathe, as well as our ability to see the stars, it’s also worth checking:
In this case, it’s pretty consistent with the total column smoke forecast, and the blue color suggests it’s not too concerning.
Visibility
If you don’t have a smoke forecast that covers your location, a visibility forecast can be a reasonable - but not fool-proof - substitute. Visibility forecasts predict “ all causes ” horizontal visibility from the ground, i.e. how far can you see before haze/mist/fog/low cloud/rain/pollution/blown dust or smoke blocks your view?
In this forecast map, the clear color means you can see farther, which is a good thing for our night time shoot. You can see there’s some more limited visibility way off in eastern Colorado. This broadly corresponds to an area of poorer transparency (see above) and some mid-level cloud.
Note that the visibility forecast is not picking up the effect of total column smoke in the western part of the state - this is because it forecasts horizontal visibility, not vertical.
Wind Gusts
Finally, wind gusts. As we’re shooting across a body of water, there’s a chance we can get some reflections of stars in the water - but only if the wind is still:
And, miraculously for the notoriously windy Rocky Mountain National Park, there are hardly any wind gusts predicted!
How did we do?
The forecast looked good.
And it turned out to be a perfect evening - still, clear, not at all cold, overall quite beautiful. Here’s the shot we planned:
Conclusion
When planning your night photography, be sure to check the critical weather variables as well as the usual questions of twilight times, moon phase and altitude/azimuth, and alignment of the Milky Way and Galactic Center.
Use Photo WX - it’s designed to give traveling photographers exactly what you need to determine relevant conditions for your shoot. With multiple weather models and variables available, plus some specialty derived weather layers (e.g. multi-level cloud, seeing + transparency), it will set you up to make the best possible decision about where and when you try to capture the night sky.
Quick Night Shoot Weather Checklist
- Check multi-level cloud cover
- Review transparency forecast (0–5 scale)
- Check seeing forecast (0–5 scale)
- Evaluate smoke (total column + near-ground)
- Confirm visibility forecast
- Assess wind conditions (for reflections or stability)
Forecast Models Used
- HRRR – High-Resolution Rapid Refresh (USA): clouds, smoke, wind
- RDPS – Regional Deterministic Prediction System (Canada): seeing, transparency
- Photo WX Derived – combined layers (e.g. seeing + transparency, multi-level cloud)