Vestly · Free tool
What to wear today? The feels-like temperature has the answer.
Fifty degrees with wind is not fifty degrees in the sun. The tool calculates the feels-like temperature (wind chill in the cold, heat index in the heat), adds your effort and your sensitivity to cold, then suggests the layers to wear: base, middle, outer, bottoms and accessories.
- Free, no account
- Calculated on your device
- Nothing you enter is sent
Your weather and your outing
The advice changes live. Nothing is read from a weather station: you enter the values.
Cool
40 °F feels like
Calculation: wind chill. With your effort and sensitivity, the temperature to dress for is 46 °F.
How to use it
- Enter the temperature, the wind speed and the humidity from your weather report, picking °F and mph or °C and km/h.
- Say how much effort you will put in (still, walking, bike or scooter, running or sport), how long you will be out and how sensitive you are to cold.
- Tick “rain” if needed. The advice updates with every change.
- Read the five levels of the outfit, copy the summary, export it to CSV or print it.
A worked example
Case: 46 °F, wind 12 mph, humidity 70%, walking, 1 to 3 hours, average sensitivity.
Wind chill (Environment Canada formula) works out to about 40 °F felt (4.6 °C). Walking adds the equivalent of 5 °F (3 °C) of body heat: the temperature to dress for is 46 °F (7.6 °C), “cool”: a long-sleeve top, a fine sweater or cardigan, a jacket or trench coat, pants and a light scarf.
Other benchmarks: 14 °F with a 30 mph wind feels like about −7 °F; 90 °F at 60% humidity feels like about 100 °F.
Method, assumptions and limits
Method. If the temperature is 50 °F (10 °C) or below and the wind is at least 3 mph (4.8 km/h), the feels-like temperature is the wind chill (Environment Canada formula). From 80 °F (27 °C) with at least 40% humidity, it is the heat index (Rothfusz regression). Otherwise, it is the measured temperature. Heat produced by effort (0, 3, 6 or 9 °C, that is 0, 5, 11 or 16 °F) is then added, and 3 °C (5 °F) is subtracted or added depending on sensitivity. Eight levels of layers are tied to the resulting temperature.
Limits. These are general benchmarks: sun, shelter, wet clothes, age and health change everything. This is not medical advice. For children, older adults or mountain outings, apply more cautious margins. The formulas are not valid beyond their ranges (very light wind, extreme cold).
Frequently asked questions
Why add physical effort?
Brisk walking, cycling or running produces heat: you can dress more lightly than when standing still, but you need to be able to take layers off.
What is the feels-like temperature?
It is the temperature at which the air would feel as cold or as hot on skin, taking wind or humidity into account. A thermometer does not measure it.
Does the result apply to a child?
No, it is calibrated for an adult. Children cool down faster: plan one more layer.
Are my values sent anywhere?
No. No weather is read and nothing you enter leaves the page.