Field notes · Moose and the weather

When moose move: watch the thermometer, not the barometer.

Hunting lore watches the barometer. The research watches the thermometer. Here's what's been measured about moose and the weather, what's hunter experience, and what's myth.

Groundwind · 5 October 2026 · 6 min read

Temperature comes first

Moose are built for cold. In Renecker and Hudson's measurements, moose start panting to shed heat at 14 °C in summer and pant open-mouthed at 20 °C. In a winter coat the threshold is −5 °C (Renecker and Hudson 1986). GPS-collared moose cut their travel and move into shade from about 15 °C in spring and 20 °C in summer (Melin 2014; Street 2015; Broders 2012). Deer are less touchy: in a GPS study of white-tailed deer, the hour-to-hour weather made little and inconsistent difference to how far they moved (Webb 2010).

That's the working curve Groundwind scores with, built on those thresholds. On a warm day moose go to dense conifer and forested wetland, and the cutovers empty out by midday. Frosty mornings are prime.

A warm spell beds them. The first cool day moves them.

Through warm spells, moose cut their daytime movement and look for shade (McCann 2013; Street 2016). How that builds over several days hasn't been measured. It's hunter experience, and it's consistent: a run of warm days beds them through the heat and they move at night, and the first cool day after is the one to be out. Groundwind reads the last ten days of highs beside the forecast for it:

• The third day or later of highs of 18 °C or more: bedded through the heat, moving at night.
• The first cool day after two or more warm ones, with a high 5 °C lower or under 14 °C: expect movement.
• An overcast, cool day under 14 °C stretches the morning movement toward midday.

The barometer

We found no peer-reviewed evidence that barometric pressure itself moves moose or deer, and in the deer study above the day-to-day weather barely registered (Webb 2010). What comes with a cold front does: the temperature drop and the clearing behind it. So watch the thermometer instead. A drop of 5 °C or more in a day, with the wind easing, is the change worth getting out for.

Rain

There's little research on moose and rain, so this part is hunters' experience. Light rain quietens the woods underfoot, which makes it good still-hunting weather. Heavy rain, over about 3 mm an hour, is different: it kills calling and cuts how far you see.

Wind

How wind changes what moose do is barely studied. Its effect on you is plain: wind cuts how far a call carries, covers the sound of an animal moving and swirls your scent. On a windy day hunt the lee slopes and the dense conifer, where hunters find them bedded. There's more on setting up for the wind in Calling moose with the wind, and on the light-wind days in Hunting thermals.

Time of day and the rut

Moose move most at dawn and dusk. Groundwind counts the best hours as half an hour before sunrise to three hours after, and three hours before sunset to half an hour after. Bulls are a little more active by day than by night overall (Klassen and Rea 2008). In Ontario, breeding peaks in the last week of September and the first week of October, centred on about 1 October, and bulls answer a call best from about 25 September to 5 October.

The moon

A GPS study of white-tailed deer found no effect of the moon's phase on how they moved (Webb 2010), and we found nothing published for moose. Groundwind shows the moon and doesn't score it.

Where to look in the fall

• Browse: cuts and burns 5 to 20 years old, and open mixedwood. A cut under 5 years old is mostly avoided until the cover grows back (Ontario MNR 1988).
• Close to cover: in a study of winter browsing on northern Ontario clearcuts, 95% of it was within 80 m of cover (Hamilton 1980). The edge where a 5 to 20-year cut meets conifer is the best ground there is.
• Water: summer feeding in lakes and at licks is about sodium, and it's mostly over by fall (Fraser 1982, 1984). But in the rut cows and calves gather near lakes, beaver ponds and marsh edges, and the bulls come to them.