Running weather, in words a coach would use

What does the coach say about the weather?

As you start: how warm or cold the day is, and what to do about it. On a hot, humid or cold day it says so again later in the run, when it helps most. Always in words. You'll never hear a temperature read out.

Why words instead of degrees?

Because a number doesn't tell you what to do, and words can. “Muggy” says breathing will feel heavier, and that it isn't your fitness. “Cold one” says give the first minutes time. A coach's job is to tell you what the weather means for the effort, not to read you a forecast.

How do heat and cold change a run?

Heat makes your heart work harder at the same pace, which is why it gets the most words. Your body sends more blood to the skin to shed heat, and humid air slows the cooling further. Last week's comfortable Easy pace can sit higher in your heart rate today. Cold has the opposite problem: muscles take longer to warm, and heart rate is slower to come up in the first minutes.

For why heart rate climbs on a long, warm run, read zone 2 running.

Why doesn't it mention rain, snow or wind?

Because a forecast can be wrong about the minute you're in, and being told it's raining under a dry sky is the fastest way to stop trusting a voice in your ear. Warmth and humidity change slowly across a run, so the coach can speak to them honestly. Rain, snow, wind and the sky change minute to minute, so it leaves them alone.

How does Adjust for heat change my paces?

It eases them. Heat makes the same pace cost more, so with Adjust for heat on in Your gears, a hot day eases your pace ranges: Easy stays easy, Steady stays steady. The start screen shows when your paces are eased for warmth. Running at altitude eases them too.

Heart rate guards every run as well. If the heat shows up as your heart rate climbing at the same pace, the coach eases the pace and tells you why:

Does weather talk need a connection?

Only before the run. The forecast is fetched before you start, when there's a connection. The run itself needs no signal: with no forecast to hand, the weather line stays silent and everything else is coached as usual.

To fetch a forecast, Gears sends the weather service your approximate place, rounded to about a kilometer. Weather data from MET Norway, CC BY 4.0. See privacy.

Can I turn weather talk off?

Yes. Weather talk is on by default, with its own switch in Settings on iPhone and on Apple Watch: “As you start, your coach says how warm or cold the day is, and says it again on a hot, humid or cold day.”

What Gears doesn't do

• It doesn't read out temperatures, or forecast the rest of your day.
• It doesn't mention rain, snow, wind or the sky.
• It doesn't fetch weather during a run. No forecast before the start means no weather line.
• It doesn't tell you whether it's safe to run in extreme heat or cold. That's your call. Read the health disclaimer.