Tool
Horse weather: grass, heat, insects and rugs
This calculator is being revised. Its results use general rules that have not passed our source review. Do not use them as care advice for your horse.
What it does
- Turns today’s weather into grass, heat, insects and tonight’s rug.
- Warns of gales and of a cold night followed by sun.
- Puts your input in the link, so you can keep or share the result.
What it doesn’t do
- Doesn’t fetch a forecast: you enter what your weather app says.
- Doesn’t know your horse: it looks at the weather, not at the field or the coat.
- Never gives the all-clear; it only says when to look more closely.
What happens to your input
What you enter stays in your browser and in the link. Nothing is sent to a server; we only count that the tool was used.
What the four cards weigh up
Grass. Grass makes sugar in the sun by day and uses it up at night, but only when it is warm enough (roughly above 5 °C / 41 °F). After a cold night with sun there is more sugar by afternoon than in the morning; in frost it all stays put; and when rain follows a dry spell the grass grows again and brings its stored sugars with it. In those situations the card tells you to take care. It never says it is safe: that depends on your horse and your field.
Heat. The card uses the heat index common for horses in the United States: the temperature in Fahrenheit plus the relative humidity in per cent, at the warmest hour. Under 130 there is nothing to do; between 150 and 180 you work shorter and easier; above 180 you don’t. Because you choose the humidity from three options, the card calculates with 40, 60 or 80 per cent.
Insects. Flies and horseflies come well above 12 °C (54 °F) with little wind; midges (sweet itch) in muggy, still weather around dawn and dusk. Strong wind and heavy rain damp them down.
Rug. The same ladder as the rug guide: tonight’s lowest temperature, with wind and rain taken into account, for an unclipped and a clipped horse with shelter.
Questions
Where do I find these values?
In your weather app or on your national weather service’s website, for the place where your horse lives: today’s high, last night’s and tonight’s low, the sun, the rain, the wind and the humidity. If you are unsure between two options, choose the stricter one.
Can I get this every day without entering anything?
In Halster, Care advice does this with the forecast for your yard’s location and what you have entered about your horse. Halster is not yet available in the App Store; join the waitlist to hear when it is.
Does it work outside Europe?
Yes. You enter the values yourself, so it works anywhere. In the southern hemisphere the seasons are reversed; the cards only look at today’s weather. If your browser is set to US English, the temperatures start in °F.
In Halster
Keep track of today’s checks
Note what you checked today about your horse’s water, shade and blanket in Halster.
Install the test version through TestFlight.
Read next
Sources