Should you ride today or tomorrow?

You checked the forecast on Sunday night. Looked fine. Mild, a bit of wind, no rain until evening. You set off at 9am feeling optimistic, turned onto the exposed section past the reservoir, and spent the next 40 minutes grinding into a 20km/h headwind that the weather app on your phone showed as a perfectly innocent little arrow pointing vaguely east.

That arrow had no idea you were heading east.

This is the problem with generic cycling weather forecasts, and it's why "should I ride today or tomorrow?" is almost never really a question about rain or temperature. It's a question about wind direction relative to your specific route, and timing.

The good news: that question is answerable. Precisely, and in about 30 seconds.

The question isn't "what's the weather?" it's "which hours suit my route?"

Wind direction relative to your route is everything. A westerly wind might give you a gloriously fast outbound leg on a route that heads west to east, then punish you all the way home. The same wind on a north-south circuit might mean sustained crosswinds. The same wind on a different day, at a different hour, might have rotated 20 degrees and turned your usual loop into something genuinely enjoyable.

Generic weather apps report conditions at a pin on a map. You don't ride at a pin on a map. You ride 60, 80, 120 kilometres across terrain that changes direction constantly.

The asymmetry matters too. According to Yellow Jersey's analysis (February 2020), every additional 5km/h of headwind costs roughly 10% of your speed. A 15km/h headwind doesn't just slow you down by 15km/h divided by your speed. The aerodynamic drag compounds. You're working significantly harder to go the same speed, or you're going significantly slower for the same effort. A tailwind of the same speed helps, but not by the same margin, because you're less exposed to it at pace. That's the effort trap: headwinds punish disproportionately. A day that looks manageable on a weather widget can absolutely hollow you out if your route happens to point into the wind for the bulk of the ride.

This is why route wind analysis matters far more than a spot forecast.

How to decide today vs tomorrow in under a minute

Tailwind GPS scores your route hour by hour on a 0-100 scale, factoring in your typical pace pulled from Strava so the score reflects where you'll actually be on the route at any given moment, not where an average rider might be.

The scoring bands are:

• 80-100: Excellent. Expect favourable tailwinds for most of the ride.
• 55-79: Great riding conditions.
• 40-54: Neutral.
• 20-39: Challenging.
• 0-19: Prepare for a tough ride.

Here's the workflow:

1. Connect your Strava account (your regular routes appear automatically) or upload a GPX file, or draw your route directly on the map.
2. Open the hourly view for today and for tomorrow.
3. Set your personal threshold. For most club and endurance riders, "55 or above" is a reasonable minimum for a quality session. Below 40, you're in headwind territory.
4. Check the rain timing. The rain window shown is route-specific. A shower forecast for 3pm matters a lot more if you're still 30km from home at 3pm than if you're back by 2.
5. Look at the directionality breakdown: tailwind %, headwind %, crosswind %. For threshold or endurance work, lower headwind % usually means better quality. For a deliberate strength session, Tailwind GPS has a headwind training mode that highlights exactly the conditions you want to suffer through.
6. Compare the two days side by side. If today scores 48 and tomorrow scores 71 at 8am with a clear rain window, the answer is tomorrow.

For Strava route weather planning, the whole thing takes seconds once your routes are loaded.

When both days look acceptable

Sometimes today scores 58 and tomorrow scores 63. Not a dramatic gap. Here's how to break the tie:

First, look at the rain window. Even a small score advantage is worth taking if it comes with a genuinely dry ride versus a damp one. A score of 58 on a dry morning often feels better than 63 with a 40% chance of showers at the midpoint.

Second, check the tailwind percentage rather than just the overall score. A score of 60 driven by 55% tailwind and 10% headwind is a very different ride from a score of 60 built on 30% tailwind and 35% headwind. The numbers are close; the experience isn't.

Third, consider crosswinds. A high crosswind percentage isn't necessarily dangerous, but on exposed or technical sections it adds fatigue and reduces confidence. If you're already tired from a week of training, the lower-crosswind option is the more honest choice.

Finally, match the day to the session. If Tuesday is your interval session and Saturday is the club ride weather planning day, a challenging-but-acceptable score on Tuesday might be exactly right for the work you're trying to do. A score of 72 on Saturday matters more when the whole group is deciding whether to show up.

How accurate is tomorrow's forecast, honestly?

Short answer: good enough to make meaningful decisions, with caveats.

NOAA NESDIS data (August 2025) puts five-day forecast accuracy at roughly 90%, and seven-day at around 80%. The Met Office provides hourly forecasts for the first two days, then three-hourly from day three onwards. That matters: the closer you are to the ride, the more reliable the timing becomes.

Rain timing is the most volatile variable. A forecast showing rain at 2pm might shift to 1pm or 4pm by the following morning. So: use the hourly route score as your planning baseline, but check again the evening before or morning of the ride. The overall picture (is tomorrow going to be a tailwind day or a headwind day?) is reliably set 24-48 hours out. The precise minute the shower arrives is not.

This is exactly why hourly scoring for cycling routes exists as a concept: not to give you false precision, but to give you a decision framework that's far better than a weather widget.

The headwind reality check

Worth stating plainly: a 20km/h headwind is not the same as a 20km/h tailwind in the opposite direction.

At 30km/h on the bike, a 20km/h headwind means you're moving through air at 50km/h. Aerodynamic drag scales with the square of airspeed. You're fighting roughly 2.8x the drag you'd experience in calm conditions. A 20km/h tailwind reduces your effective airspeed to 10km/h. Much more manageable, but the benefit is nowhere near symmetrical with the penalty.

This is why a route that heads into the prevailing wind on the outbound leg and returns with a tailwind feels harder overall than the scores from a simple wind arrow would suggest. The outbound suffering outweighs the homeward help.

Route-specific scoring accounts for this by analysing every segment direction against the wind forecast, not just giving you a single average. That's the practical difference between a cycling weather forecast and a generic weather app. See how wind-aware cycling apps compare if you want the broader landscape.

FAQ: planning today vs tomorrow

Which matters more: wind direction, wind speed, or rain timing? Wind direction relative to your route first, then rain timing if you're comparing close scores. Wind speed matters most when it's above about 20-25km/h; below that, direction dominates.

How early should I check? Set a baseline 2-3 days out (good for block planning and club ride coordination), then confirm the evening before. Rain timing in particular shifts between those checks.

Should I avoid crosswinds completely? Not necessarily. Crosswind percentage in Tailwind GPS shows what proportion of your route you'll face sideways wind. Above 60-70% crosswind exposure at speed, it's worth factoring in comfort and fatigue, particularly on exposed climbs or descents. It's not a disqualifier, just a variable.

Can I plan ahead for a training block or sportive? Subscribers get a 14-day forecast window across up to 40 routes. That's enough to slot in key training sessions around genuinely good weather windows, not just react to tomorrow's conditions. For sportive weather and wind advice, it's the only way to make a confident call more than three days out.

Does the Tailwind Score account for my pace? Yes. The score is personalised to your expected riding speed via Strava, so the forecast reflects where you'll be on the route at each moment, not an assumed average.

Try it on your route

If you've got a favourite loop, the decision between today and tomorrow becomes obvious once you can see both days scored side by side. Connect Strava and your existing routes load automatically. Or upload a GPX, or draw directly on the map and export GPX for your head unit at the end.

The free plan covers three routes and a three-day forecast, which is enough to get a proper feel for whether the scores match your real experience on the road. Subscribers unlock up to 40 routes, a 14-day planning window, rain alerts, and weekly ride summaries for $2.99 a month (or $19.99 a year, with a 7-day free trial).

For riders deciding between Tuesday intervals and Saturday's club run, the wind-aware hard and easy day framework is worth a look too.

Stop reading weather apps designed for people standing in their driveways. Score the route you're actually going to ride.

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