“Which underquilt should I take?” and “What will the weather mean in a hammock?” sound like simple questions. Neither can be answered by one product number. The overnight low, wind exposure, your own cold tolerance, clothing, insulation above you and the fit of the underquilt all matter.
We built two free tools to make those decisions easier. They show their reasoning and require no account. They are planning aids based on Momo Jord’s field guidance, not laboratory tests, medical advice or a substitute for official weather warnings.
1. Underquilt calculator
Open the underquilt calculator →
You enter the expected overnight low from −25 to +20 °C and choose how exposed the site is, whether you normally sleep warm or cold, what you plan to wear and whether your top insulation matches the conditions.
The calculator adjusts a planning temperature for exposure, personal cold tolerance and clothing. It then selects the lightest current Momo Jord underquilt whose published comfort guidance covers that adjusted value: UQ300 about +5 °C, UQ400 about 0 °C, UQ500 about −2 °C and UQ800 about −10 °C. The top-insulation answer is a separate check; it does not make the calculator choose a lighter underquilt.
These values are Momo Jord guidance based on our own and customers’ experience. They are not ISO-certified underquilt temperatures or exact thresholds. If the adjusted temperature falls below the UQ800 guidance, the result warns that the range is exceeded rather than pretending that the model can guarantee warmth.
2. Hammock Weather
Search for a place or place the pin on the map. The tool requests a seven-day forecast from Open-Meteo and displays the daily minimum temperature, maximum wind speed and precipitation total. It applies the same Momo Jord underquilt guidance, with additional planning margins when the forecast wind reaches 12 km/h and 25 km/h. You can also add a “sleep cold” margin.
Each night receives a simple green, yellow or red planning label. That label is a transparent site heuristic, not an official danger level. Forecasts can change and the model cannot see local gusts, falling branches, flooding, fire restrictions, your experience or your health. Check the relevant national weather service and local warnings before leaving.
How to use the result
- Enter the expected campsite, not the nearest large town if conditions differ.
- Use the overnight low, not the daytime temperature.
- Be honest about exposure and whether you tend to sleep cold.
- Check that your sleeping bag or topquilt is suitable for the same conditions.
- Add more margin for remote trips, uncertain forecasts or an unfamiliar setup.
- Test new equipment close to home before relying on it.
For the background behind the numbers, read what underquilt temperature guidance can and cannot tell you or the broader underquilt guide.
Data and method
- Momo Jord underquilt calculator: current model, inputs and limitations.
- Momo Jord Hammock Weather: seven-day planning view.
- Open-Meteo forecast API documentation: source of forecast data used by Hammock Weather.
Tool behaviour and links checked on 12 August 2026.
