How GoodDayTo scores your day

The short version

GoodDayTo combines real forecast data with activity-specific rules. A good day for drying laundry is not automatically a good day for cycling, a picnic or stargazing, so each activity uses different weather signals and different tolerances.

The result is a planning score from 0 to 100. Scores of 75 or higher are shown as GO, scores from 50 to 74 as WAIT, and lower scores as NOT TODAY. These are practical planning recommendations, not safety clearances or professional advice.

Why we score a window instead of one perfect hour

Weather tools can be misleading if they cherry-pick a single unusually good hour. GoodDayTo searches upcoming conditions and scores usable multi-hour windows. Ordinary ups and downs blend the average score with the weakest hour in that period, so a shower, gusty hour or temperature spike cannot disappear inside an otherwise attractive average. A hard safety cap in any selected hour also caps the entire window; two pleasant hours cannot dilute a thunderstorm, freezing precipitation or another capped condition.

Practical example: if the first two hours of a three-hour ride look ideal but the final hour carries a thunderstorm signal, the whole three-hour window stays NOT TODAY. Choose a different continuous window or a safer day.

Match the score to the time you actually have

GoodDayTo lets you plan for 1 hour, 3 hours or a half day (five forecast hours). Changing this setting changes the window we score and can change which activity ranks highest. A short dry gap may be excellent for a one-hour walk but not reliable enough for a half-day hike or outdoor job.

The end time is shown as the end of the full planning block. For example, three forecast hours starting at 14:00 are displayed as 14:00–17:00, not 14:00–16:00. The selected planning length is stored locally in the browser so it remains useful on the next visit.

Weather signals we use

• Temperature and apparent temperature — used differently for physical activities, outdoor jobs and leisure.
• Precipitation probability and measured forecast precipitation — especially important for laundry, washing a car, riding and picnics.
• Wind and wind gusts — critical for cycling, motorcycling and exposed outdoor activities.
• Relative humidity — particularly useful for estimating whether outdoor laundry conditions are favourable.
• Cloud cover — important for stargazing and relevant to beach conditions.
• UV index — used as a caution factor for exposed physical activities and beach weather.
• Day/night status — used where visibility and daylight materially change the activity.
• Weather codes — thunderstorm signals can cap scores rather than letting a good temperature hide a serious weather concern.

Activity-specific logic

Every activity has its own scoring model. Laundry benefits from lower humidity, low rain risk and a useful breeze. Running values comfortable apparent temperature and manageable wind. Cycling and motorcycling penalise rain, wind and gusts more heavily. Football rewards comfortable, drier conditions with manageable wind, while playground visits also account for UV and practical daylight. Exterior painting strongly penalises rain risk, high humidity and stronger wind because a single dry hour is not enough for a useful working window. BBQ and picnic scoring cares about rain, outdoor comfort and wind. Beach scoring values warm conditions while treating strong wind and very high UV as cautions.

GoodDayTo also shows the main factors that helped or hurt the live score. That explanation is generated from the same forecast values used by the score, so the displayed reasons are not generic filler.

Does the time actually make sense?

GoodDayTo also considers whether an activity normally makes sense at that time of day. A technically dry, calm evening should not make Golf the best evening suggestion, just as a clear afternoon should not make Stargazing a daytime recommendation. GoodDayTo also checks whether that time of day makes practical sense for the activity.

Golf, lawn mowing, gardening, exterior painting and outdoor laundry strongly favour normal daytime hours. Hiking, cycling, motorcycling, beach visits, playground trips and kite flying favour daylight but can allow some evening flexibility. Football and tennis can extend into early evening, but GoodDayTo does not assume floodlights. BBQ and picnic naturally fit afternoon and evening, while dog walking and running are more flexible. Stargazing is deliberately restricted to evening and night conditions when darkness is appropriate.

These rules are designed around typical everyday use, not absolute bans. A lit driving range, night run or twilight ride can still be possible in real life; GoodDayTo simply avoids presenting those edge cases as the default best activity for most people.

Safety caps

Some conditions should not be treated as just another small deduction. When thunderstorm codes, freezing drizzle or rain, snow, fog, very strong gusts, extreme apparent temperatures or Dog Walking heat thresholds appear anywhere in the selected forecast window, GoodDayTo applies the most conservative relevant cap to the whole window for activities those conditions materially change. This prevents pleasant hours elsewhere in the same period from producing an unrealistically positive result.

Local warnings, road conditions, beach flags, currents, lightning alerts, trail closures and official emergency information can still override any GoodDayTo result. Always use local official information where safety matters.

Stargazing is different

Stargazing needs more than a generic night-time weather forecast. When astronomy data is available, GoodDayTo combines cloud, rain and wind with astronomical darkness, moon phase, moon illumination and whether the moon is above the horizon. Bright moonlight can reduce the visibility of faint objects even under a clear sky.

We do not currently pretend to measure local light pollution, atmospheric seeing or transparency from the browser. Those limitations are stated because a trustworthy score should be clear about what it does not know.

What GoodDayTo does not claim

GoodDayTo is not a certified safety system, a medical heat-risk service, a marine forecast, a road-surface sensor or a substitute for official warnings. The score is a practical interpretation of available forecast inputs for everyday planning.

We also avoid inventing readings that a browser or forecast provider cannot genuinely supply. If a future activity needs data we cannot measure reliably, we will either add a legitimate source, state the limitation clearly, or not claim to score that factor.

Data sources and refresh behaviour

The main hourly forecast and place-search inputs come from Open-Meteo. GoodDayTo requests the weather fields needed by the activity models and calculates the final GO, WAIT or NOT TODAY result in the site logic rather than importing a ready-made activity rating from a provider.

Stargazing makes a secondary request to Sunrise-Sunset.org for moon and astronomical-darkness timing. If that request is unavailable, GoodDayTo refuses to invent a weather-only Stargazing score and offers a retry. Photography uses the same provider’s location- and date-specific golden- and blue-hour ranges to rank otherwise practical weather windows; if that lookup fails, Photography falls back to its weather-only model and says that exact light timing was unavailable. Attribution is displayed whenever astronomy data is used.

Nearby-place context uses OpenStreetMap data. Nominatim is used for readable reverse-geocoded place labels, while selected local-fit checks use Overpass-compatible endpoints. Those checks never change a weather score into a claim that a venue is open, permitted or safe.

The browser keeps a short-lived forecast cache to improve speed when moving between pages. Weather cache lifetime is intentionally measured in minutes. Nearby-place lookups can be cached for hours because map features are less time-sensitive. Refresh controls invalidate the weather cache and request fresh forecast data.

Location and privacy

You can search for a town or allow the browser to provide your location. The site uses the resulting location to request forecast data. Favourites, unit preferences and your selected planning duration are stored locally in the browser so they can work without creating an account. Shared result text does not include latitude or longitude.

How we decide whether an activity deserves its own page

GoodDayTo does not add an activity simply because another search phrase exists. A new public activity should answer a distinct planning question, have weather sensitivities that are meaningfully different from an existing tool, use sensible time-of-day or duration rules, and explain what the forecast cannot know. If two ideas would use effectively the same model and add no useful decision context, creating separate pages would add clutter rather than value.

Each new activity is expected to include a working live calculation, useful explanatory content, clear limitations, internal links and a place in the wider activity structure. We also teach the Planner normal-language phrases for the activity so the visitor can search naturally instead of needing to know the exact page title.

This quality rule is also part of our SEO and advertising approach. GoodDayTo is intended to earn visibility from useful tools and original explanations, not from mass-producing thin keyword pages. Our weather planning guides provide deeper educational context where a topic deserves more explanation than the live result screen should carry.

Current coverage

GoodDayTo currently supports 61 direct activity weather checks, grouped across sports and fitness, home and garden jobs, outdoor adventures, family plans and events. The models are not static: thresholds, timing rules and limitations can be refined when testing exposes a genuine problem, but changes should preserve the meaning of the activity rather than chase a higher-looking score.

Examples of genuinely different weather decisions

New activities are only useful when the weather decision actually changes. Outdoor Cinema is evening-first and cares about seated comfort, rain and wind across a full screening. Fruit Picking is a daylight outing where heat, UV and wet ground can matter over several hours.

Hedge Trimming uses a stricter low-wind, dry-daylight model because moving branches, tools and footing make gusts more relevant than they are for general gardening. Metal Detecting can tolerate some damp weather but still depends on daylight and comfort, while permission, protected sites and digging rules remain deliberately outside the weather score.

Those differences are why GoodDayTo does not publish one generic outdoor score under many page names. The page has to solve a distinct planning problem or it does not belong in the index.

Why the model will keep improving

GoodDayTo is designed to be auditable. We review activity thresholds, edge cases and user intent before adding new activities. When the scoring method changes materially, we update this methodology and the relevant activity guidance rather than silently changing the meaning of the score.