|Describes features that depend on seasonal conditions|
|Used on these elements|
|Status: in use|
|Tools for this tag|
Useful for features which appear or disappear with differing seasonal conditions. Wetlands can dry out in the summer, ponds can disappear entirely in hot weather. Grocers/farmer's markets might be open only in the warmer season and rural roads might close from the first snow until thaw.
|seasonal=spring/summer/autumn/winter/wet_season/dry_season/...||describes exact season (if possible) when feature is present.|
Implies seasonal=yes for that season. Note these values can be ambiguous for features that that vary between different states since it can be unclear which state occurs at which time of the year.
|seasonal=no||to indicate that a feature is not seasonal although it is expect to be (for instance a road that is not seasonal in an area with a lot of seasonal roads)|
OSM uses British English, thus autumn not fall.
You could consider using a semi-colon value separator (;) to specify several seasons, but please note that very few applications actually support this.
This tag is described as having freeform value. For waterways (waterway=river, waterway=stream, waterway=canal, waterway=ditch, waterway=drain) it is used over 100 000 times with - as of December 2017 - the following values being used more than 20 times:
- Conditional restrictions could be used to give approximative opening dates. Ex: access:conditional=no @ Nov-Apr.
- Proposed features/Dry weather
Relation to intermittent
Depending in interpretation first tagging may be similar to tagging highway=motorway + motor_vehicle=yes (adding pointless detail) or second may be like tagging only parking=surface without amenity=parking (adding only highly detailed tag and expecting that data consumers interested only in much more general data will still use it)
Note that as it is much simpler (only boolean values) and much more popular it is more likely to be used by data consumers.