One answer, not a dashboard
No pressure charts, no hourly scrolling. Gwhen names the time and tells you why in a sentence.
Know when to go.
Best time for outdoor plans. Gwhen reads the forecast and answers a single question — when to go. Precise time windows for cycling, running, walking, tennis and dinner outside.
Availability
Coming soonComing soon
Learn moreHow it works
Designed for iOS · Lock Screen, Dynamic Island and Live Activities
9:41
Wednesday, Aug 12
Today
Three good openings today. The morning one is the best you'll get this week.
Road RideExcellent
6:20–7:50 AM
Stroller WalkGood
5:40–6:30 PM
Tuned to your activity
A road ride and a stroller walk want different weather. Set thresholds once; Gwhen judges accordingly.
Honest when it's bad
When nothing is genuinely good, Gwhen says so — and shows the least-bad option instead of faking confidence.
The signature
A timeline that shows the window opening.
Closed, opening, ideal, closing. The recommended stretch lifts out of the day with a soft silhouette, so you read the shape of the morning before you read a single number.
Best window today
6:20–7:50 AM
5AM6AM7AM8AM10AM
6:20–7:50 AM
Cool temperatures, light wind and dry conditions make this today's strongest riding window. Wind picks up noticeably after 8.
How it works
Four steps from forecast to decision.
Forecasts shift more often now. Gwhen re-evaluates every hour, for every activity, so the window you saw at sunrise is still the right one when you actually head out.
- 01
Choose an activity
Road ride, run, stroller walk, tennis, dinner outside — or something of your own. Each one starts from a sensible profile.
- 02
Say what good means
Temperature range, wind tolerance, rain patience, how much daylight you need. Two or three taps, then never again.
- 03
Gwhen scores the day
Every interval in the forecast is graded Excellent, Good, Fair or Poor against your thresholds, then smoothed into continuous stretches.
- 04
You get one time
The strongest continuous stretch becomes the recommended window, with a one-line reason and the conditions that back it up.
9:41
Wednesday, Aug 12
Today
Three good openings today. The morning one is the best you'll get this week.
Road RideExcellent
6:20–7:50 AM
Stroller WalkGood
5:40–6:30 PM
The four condition states
Excellent
Everything lines up. Go.
Good
Comfortable, with one soft caveat.
Fair
Doable if you're motivated.
Poor
Gwhen won't pretend otherwise.
On your Lock Screen
A live countdown to your window.
Gwhen runs as a Live Activity, so the time until your window opens sits on the Lock Screen and in the Dynamic Island — counting down, updating itself, no app to open.
Counts down, not up
Hours, minutes, seconds until the good stretch begins.
Re-times itself
If the forecast shifts the window, the countdown quietly re-targets.
Glanceable quality
The condition state and the window's shape travel with the countdown.
5:04
Wednesday, August 12
5:04
GwhenExcellent
Road Ride window opens in
1:24:00
calm · 52° · dry6:20 – 7:50 AM
Road Ride opens in
1h 24m · 6:20 AM
Calendar-aware
Find openings that already fit your day.
Let Gwhen see your free time and the weather at the same time. It checks around existing commitments so the window it recommends is one you can actually use.
Google Calendar
Works with personal and work calendars to find free gaps.
Outlook
Respects meetings and focus time when suggesting a window.
Apple Calendar
Native iOS integration for calendars already on your phone.
Pricing
Free to decide. Pro to plan.
No ads, no data resale, no upsell theatre inside the app.
Free
$0
One activity, today's window
- —One saved activity
- —Today's recommended window
- —Plain-language reasoning
- —Light and dark
Pro
$3.99
per month, or $29 a year
- —Unlimited activities
- —Seven-day outlook per activity
- —Custom thresholds and tuning
- —Lock Screen alerts and Live Activities
- —Multiple locations
FAQ
Questions
- Do I need Pro to get a useful answer?
- No. The free tier gives you a full, honest window for one activity every day. Pro is for people tracking several activities or planning further ahead.
- Where does the forecast come from?
- High-resolution hourly forecast data, re-scored locally against your own thresholds so the judgement is yours, not a generic weather grade.
- Why does a window-finder matter more now?
- As weather becomes more variable, the gap between a good hour and a poor one widens. Gwhen treats that volatility as the point — it keeps re-checking so the window you planned on is still the right one when you leave.
- What happens on a bad weather day?
- Gwhen tells you plainly that nothing is good, and shows the least-bad option with a caveat rather than promoting a poor window.
- How accurate is the recommended window?
- As accurate as the hourly forecast underneath it. Gwhen refreshes through the day, and a window can shift or narrow as the forecast firms up — you'll see the change, not a stale answer.
- Can I track more than one location?
- Yes, on Pro. Each activity can carry its own location, so a home ride and a weekend trailhead are scored separately.
- Which activities are supported?
- Road ride, run, walk, stroller walk, tennis, dinner outside and more ship as starting profiles. You can also create your own and set exactly what good means for it.
- Can Gwhen check my existing calendar?
- Yes. Connect Google Calendar, Outlook or Apple Calendar and Gwhen will look for windows that already fit around your meetings, school runs and commitments.
- What does Gwhen do with my data?
- Nothing beyond giving you an answer. No ads, no data resale, no third-party trackers. Calendar access is only used to find free openings, not to build a profile.
- Is it on Android or the web?
- Gwhen is designed for iOS first, including Lock Screen alerts, Dynamic Island and Live Activities. Other platforms aren't available yet.
- Can I cancel anytime?
- Yes. Pro is billed through the App Store — cancel in a couple of taps and you keep Pro until the period ends, then drop back to the free tier.
Go when it's good.
Add the activities you care about. Gwhen watches the forecast and tells you the one time worth clearing your calendar for.
Coming soonComing soon