01base
Smartwool Classic All-Season Merino Crew
150 g/m² merino
A specific base weight, rather than a bulky everyday sweatshirt.
FOR THE RUN BEFORE THE SUNWhat to wear for
What to wear for
your winter run.
Real forecast. Your exact run hour. The right layers.
Spend less time guessing at the door.
Get out there and find your stride.
A COLD MORNING, SORTED.DEMO KIT
26°F
14 mph wind
14°F running estimateLight layers.
Windproof where it counts.
Windproof where it counts.
Merino baseWind shellWarm mittens
Illustrative 26°F kit. Not a live forecast.
WIND-AWARE LAYERS DARK-HOURS READY GEAR YOU ACTUALLY NEEDPOWERED BY OPEN-METEO ↗
01 / YOUR NEXT RUN
Set the run. See the kit.
Your weather, not a generic temperature chart.
THE RUNA few details. All the difference.
All times are local to your running location.
Made for the miles, not the doorway.Warmth builds as you move. Start comfortably cool, then adjust to what your body tells you.
City search: © OpenStreetMap contributors via Nominatim. Explicit searches only, cached and rate-limited. Usage policy.
THE LAYERSDEMO PREVIEW
Chicago, IllinoisEXAMPLE · 06:00
Air temperature26°F
Running feel ⓘ14°F
−15°5°25°45°65°
● Air ◆ Running estimate · apparent 16°F + our 6.5 mph headwind adjustment
09 ZONES · ONE LESS GUESS
- 01headThermal merino beanie
- 02neckLight merino neck gaiter
- 03handsInsulated windproof mittens
- 04baseMerino 250 long sleeve
- 05shellLight windproof running shell
- 06legsThermal running tights
- 07socksCushioned merino crew socks
- 08tractionRegular running shoes; check surface
- 09lights325+ lm headlamp + reflective vest
14 mph NWWind at run hour
10% precipNo precip indicated
07:18 / 16:47Sunrise / sunset · local
Demo forecast · illustrative, not live weather · 2025-01-15 at 06:00 · America/Chicago
Requested coordinates 41.8781, -87.6298
Why these layers?↗
- 14 mph wind at 26°F gives an estimated running feel of 14°F. A wind shell blocks moving air without a heavy jacket.
- Neutral warmth preference keeps our baseline. 30-60 minutes at easy effort keeps warmth in the plan.
- Your run overlaps hours outside sunrise-sunset. Bring a headlamp and a separate reflective vest; a light does not replace reflectivity.
- No ice signal in the modeled 24-hour history. This is not an all-clear for your sidewalk.
A NOTE FOR YOUR RUN
This demo shows how wind protection and lighter, breathable layers work together. Set your location for a kit built from your forecast.
Clothing choices come from our published rules below.Demo checklist available. Look up your forecast to save a real kit.
CHANGE A SETTING. YOUR LAYERS UPDATE LIVE.
02 / FILL THE GAPS, NOT THE CLOSET
EXAMPLE GEAR SHORTLISTOnly what this run calls for.
Own it already? Use it. Need something? Here's the spec to look for.
As an Amazon Associate we earn from qualifying purchases. Check the current price and rating on Amazon. No sponsored rankings.
02shell
Kiprun Run 100 Windproof Jacket
Light windproof shell with ventilation
Cuts wind; insulation comes from the layer underneath.
03hands
TrailHeads Insulated Convertible Mittens
Insulated mitten; add liners in deeper cold
Match hand protection to wind and moisture, not torso warmth. Check the fit over your liners.
04legs
Brooks Momentum Thermal Tight
Thermal full-length running tight
Thermal running tights. Add any extra base or wind brief listed in your kit.
05socks
Smartwool Run Targeted Cushion Crew Socks
Merino blend, crew height
Covers the ankle gap. Keep enough space in your shoe to move your toes.
06lights
Black Diamond Deploy 325 Headlamp
325 lumens, rechargeable
Lights the surface during your dark run window. Verify battery runtime for your full run.
07reflective
Nathan Streak Reflective Vest
Reflective coverage, separate from headlamp
Your forecast overlaps darkness; a headlamp alone does not make you visible from every direction.
The specifications matter more than the logo. Check sizing, variant details, and fit over your existing layers before you buy.
03 / THE BIGGER PICTUREBuy for the winter
SEASON PLAN · $19 ONCEBuy for the winter
your city actually has.
Three actual winters. Your city. Your usual run hour. See which conditions show up often enough to earn a place in your gear drawer.
November-March, winters 2022-23 through 2024-25. Historical counts, not a prediction. One-time $19 unlock, no subscription.
Sign in, then unlock the season profile for $19 once.
Three winters of hourly ERA5 archive data at your usual run hour, the count behind every condition, and a buy list with quantities tied to those counts. The per-run kit builder above stays free.
Account services are unavailable in this preview. The free kit builder above still works.See what is included
04 / NOTHING BEHIND THE CURTAIN
45°F → 5°FThe cold-weather layer guide.
Our full starting rules. Useful even if you never use the tool.
These are our own practical thresholds, not a study, a medical recommendation, or a guarantee of comfort.
| Band °F | Head | Hands | Torso | Legs | Feet | Wind / rain modifiers |
|---|---|---|---|---|---|---|
| 45° | Optional light cap | Optional liner gloves | Light wicking long sleeve No shell | 7-9in half tight, no base | Light merino socks | ≥10 mph: wind shell. Wet: seam-taped rain shell; waterproof hand protection when cold or requested. |
| 40° | Light ear band | Thin liner gloves | Merino 150 long sleeve No shell | Light full-length tights | Light merino socks | ≥10 mph: wind shell. Wet: seam-taped rain shell; waterproof hand protection when cold or requested. |
| 35° | Light ear band | Thin liner gloves | Merino 150 long sleeve No shell | Light full-length tights | Light merino crew socks | ≥10 mph: wind shell. Wet: seam-taped rain shell; waterproof hand protection when cold or requested. |
| 30° | Thin merino beanie | Light fleece gloves | Merino 150 long sleeve Light wind shell | Midweight running tights | Light merino crew socks | ≥10 mph: wind shell. Wet: seam-taped rain shell; waterproof hand protection when cold or requested. |
| 25° | Thin merino beanie | Liners + windproof mitten shell | Merino 150 long sleeve Light wind shell | Thermal running tights | Cushioned merino crew socks | ≥10 mph: wind shell. Wet: seam-taped rain shell; waterproof hand protection when cold or requested. |
| 20° | Thermal merino beanie | Insulated windproof mittens | Merino 250 long sleeve Light wind shell | Thermal running tights | Cushioned merino crew socks | ≥10 mph: wind shell. Wet: seam-taped rain shell; waterproof hand protection when cold or requested. |
| 15° | Thermal merino beanie | Insulated mittens + liners | Merino 250 long sleeve Windproof running shell | Thermal tights + wind brief | Cushioned merino crew socks | ≥10 mph: wind shell. Wet: seam-taped rain shell; waterproof hand protection when cold or requested. |
| 10° | Beanie + face covering | Insulated mittens + liners | Merino 250 + light fleece Windproof running shell | Thermal tights + thin base | Midweight merino crew socks | ≥10 mph: wind shell. Wet: seam-taped rain shell; waterproof hand protection when cold or requested. |
| 5° | Beanie + face covering | Insulated mittens + liners | Merino 250 + light fleece Windproof running shell | Thermal tights + thin base | Midweight merino crew socks | ≥10 mph: wind shell. Wet: seam-taped rain shell; waterproof hand protection when cold or requested. |
How we get from the forecast to a clothing band
Running estimate: Open-Meteo apparent temperature plus the difference between wind chill at forecast wind + 6.5 mph and wind chill at forecast wind. We use the NWS wind chill formula only at or below 50°F and above 3 mph. This headwind approximation assumes running into the wind; actual direction, pace, shelter and sun change the experience. It is not an official feels-like forecast.
Clothing band: Running estimate +10°F for baseline running heat. Run hot +5; run cold −5; steady +4; workout +8; 60-90 minutes +3; 90+ minutes +5; stops at lights −3. A higher clothing band means fewer layers, not warmer weather. Select the highest table threshold at or below that result. 45°F is the upper band; 5°F the lower. Extremely cold or warm conditions trigger a warning.
Wet and dark: Measurable precipitation or ≥40% precipitation probability triggers the rain shell. Wet hands get overmitts when air is ≤40°F or you request them. Any overlap with darkness adds a headlamp and reflective vest. A 90+ minute run is modeled as 120 minutes; allow for more daylight exposure if you go longer.
Ice: We inspect the previous 24 modeled hours for precipitation with a crossing of 32°F, plus recent snow and freezing rain codes. Unknown data is labeled unknown. None of this confirms the actual surface temperature.
Open-Meteo forecast documentation ↗ · ERA5 archive documentation ↗
THE QUESTIONS AT THE DOORFair questions.
Fair questions.
Straight answers.
A starting point for your run.
Your experience gets the final say.
Why fewer layers than I would have worn?+
Our starting rules allow for heat generated while running: the clothing table uses the running estimate plus a 10°F baseline, then adjusts for effort, duration and your warmth preference. Start comfortably cool, not shivering. Carry an easy-to-remove layer while you learn what works for you.
What about 38°F and raining?+
That is a wet-cold problem, not just a temperature problem. Our rule adds a ventable, seam-taped rain shell and waterproof overmitts with liners. Keep your route close to shelter and change into dry clothing afterward. No fabric makes prolonged wet-cold exposure risk-free.
Do I actually need traction?+
We flag recent precipitation combined with a crossing of freezing, recent snow or freezing rain. Your icy-sidewalk setting also adds traction. This is a caution signal, not a pavement sensor: inspect the surface and choose another route if it is unsafe.
Why mittens over gloves?+
Our colder bands favor mittens so your fingers share a warm space rather than being separated. A removable liner adds flexibility. Fit matters: avoid squeezing your hands, and do not rely on an uninsulated rain shell alone for warmth.
Where does the forecast come from?+
Open-Meteo supplies the hourly weather and sunrise/sunset times for the coordinates shown. Nominatim resolves your city using OpenStreetMap. Weather is modeled, not a reading from your front door. Our running-feel adjustment and clothing choices are our own heuristics; the short AI note explains the plan and never supplies weather.