How this works
Local aurora viewing guidance for Whitehorse, Yellowknife and Iqaluit.
Velvet Hours is made by Mikayla Ericsson, after spending eighteen winters north of 60°. Every half hour it looks at five things for two spots in each town: how dark it is, how much cloud there is, where the moon is, how active the aurora is, and how much town light is in the sky. It turns them into one call.
Most nights the answer is no, and it says so.
Drop everything.
An exceptional display is more likely than not.
Go.
A display you can see is more likely than not.
More than an hour ahead, calls stop here. Go and Drop everything need a live reading.
Worth going out.
At least one in five for a display, or seven in ten for spotting some.
If you're up anyway.
At least one in five for spotting some.
No.
Less than that.
What it is not.
It is experimental. Nobody has checked these calls against the sky yet. Every call is kept, and when people report what they saw, that goes beside the call. The misses stay.
Help check the calls.
If you live in one of the three towns and you are out at night, I would like your eyes. Email me and I will set you up as an observer: mikayla@twst.studio.
About the French.
The French on this site is a machine translation. I have read it, but no French speaker has checked it yet, because there is no budget for a translator for now. When there is, a person will do it properly and this note will go. If something reads wrong, or says something I would not say, email me and I will fix it: mikayla@twst.studio.
Where the numbers come from.
Cloud from Environment and Climate Change Canada. Aurora activity from GFZ Potsdam. Sky brightness estimated from NASA's Black Marble. Horizons from terrain data. Every forecast names its sources under Where the numbers come from.
Credits and licences.
Cloud. Data Source: Environment and Climate Change Canada. The HRDPS forecast, under ECCC's Data Services End-use Licence, version 2.1.1.
Current conditions: Environment and Climate Change Canada.
Aurora activity. GFZ German Research Centre for Geosciences, the Hp30 index, under CC BY 4.0. Changed: the outlook's typical activity is the month's median of GFZ's Hp30 over dark intervals, computed by us; the nowcast's reading is GFZ's value as published. Data: Matzka et al. 2024, doi:10.5880/Hpo.0003.
Sky brightness, estimated by us from NASA Black Marble. NASA VIIRS Land Science Investigator-led Processing System. (2025). VIIRS/NPP Lunar BRDF-Adjusted Nighttime Lights Yearly L3 Global 15 arc second Linear Lat Lon Grid [Dataset]. NASA Level 1 and Atmosphere Archive and Distribution System Distributed Active Archive Center. https://doi.org/10.5067/VIIRS/VNP46A4.002
Horizons. Terrain from the Terrarium tiles. ArcticDEM: DEM(s) were created from DigitalGlobe, Inc., imagery and funded under National Science Foundation awards 1043681, 1559691, and 1542736. Canada: Contains information licensed under the Open Government Licence – Canada.
The oval on the home page. NOAA Space Weather Prediction Center, the OVATION aurora forecast, public domain. It is smoothed and brightened for the globe, so it is not NOAA's own image, and no call uses it.
The globe's map. Made with Natural Earth, public domain.
Icons from Tabler Icons (MIT licence), and the night switch adapted from Heroicons (MIT licence). The globe and the towns' scenes drawn with three.js (MIT licence) and meshoptimizer (MIT licence). Type in BDO Grotesk (licence) and JetBrains Mono (licence), under the SIL Open Font License 1.1.
The model's methods, as published. Twilight: Patat, Ugolnikov and Postylyakov 2006 (A&A 455, 385). Moonlight: Krisciunas and Schaefer 1991 (PASP 103, 1033). Airmass: Kasten and Young 1989 (Appl. Opt. 28, 4735). Sky brightness: Garstang 1986 and Cinzano et al. 2000 (PASP 98, 364, MNRAS 318, 641). Geomagnetic latitude: Shepherd 2014 (JGR Space Physics 119, 7501), computed with aacgmv2 2.7.1 (doi:10.5281/zenodo.19462137). Solar wind: Newell et al. 2007 and 2008 (JGR 112, A01206, JGR 113, A04218), for an estimate kept beside each call and used in none.
Reusing the forecasts: credits.json names each source's terms, GFZ's licence and what we changed.
What it keeps.
Nothing that identifies you. It sets no cookies and counts visits without knowing whose they are. The privacy page says what is counted, who handles it and for how long.