Glossary
Quick reference to the terms, scales and data used across the IPMA platform.
Astronomical terms related to the position of the Sun and Moon. Data is computed locally using the suncalc-php library, not from the IPMA API.
Solar Twilight Phases
| Term | Description |
|---|---|
| Astronomical dawn | Sun at −18° (sky completely dark before sunrise) |
| Nautical dawn | Sun at −12° (horizon just visible) |
| Civil dawn | Sun at −6° (enough light for outdoor work) |
| Sunrise | Upper limb touches horizon |
| Sunrise end | Lower limb clears horizon (full disc visible) |
| Golden hour end | Sun below 6° (warm, low-angle light) |
| Solar noon | Sun at highest altitude for the day |
| Sunset | Upper limb touches horizon at dusk |
| Sunset start | Lower limb clears horizon (full disc set) |
| Golden hour start | Sun below 6° (warm, low-angle light) |
| Civil dusk | Sun at −6° (enough light for outdoor work) |
| Nautical dusk | Sun at −12° (horizon just visible) |
| Astronomical dusk | Sun at −18° (sky completely dark after sunset) |
| Nadir | Sun at its lowest point (directly below) |
| Day length | Interval from sunrise to sunset |
Sun Position
| Term | Description |
|---|---|
| Azimuth | Compass bearing (0° = North, 90° = East, etc.) |
| Altitude | Angle above the horizon (negative = below horizon) |
Moon Phases (Numeric Range 0–1)
| Phase | Range |
|---|---|
| New moon | 0–0.125 |
| Waxing crescent | 0.125–0.25 |
| First quarter | 0.25–0.375 |
| Waxing gibbous | 0.375–0.5 |
| Full moon | 0.5–0.625 |
| Waning gibbous | 0.625–0.75 |
| Last quarter | 0.75–0.875 |
| Waning crescent | 0.875–1 |
Additional Moon Data
| Term | Description |
|---|---|
| Moonrise | Time of Moon's appearance above the horizon |
| Moonset | Time of Moon's disappearance below the horizon |
| Illumination | Percentage of lunar surface illuminated |
| Distance | Distance of the Moon in kilometres |
| Azimuth (Moon) | Compass bearing of the Moon (0° = North, 90° = East, etc.) |
| Altitude (Moon) | Angle of the Moon above the horizon |
Terms related to the sea-state forecast provided by the IPMA API.
| Term | Description | Unit |
|---|---|---|
| Wave height | Significant wave height of wind-generated waves (average of the highest one-third) | m |
| Wave period | Dominant period between successive wave crests | s |
| Wave direction | Compass direction waves are travelling toward | compass |
| Total sea | Combined height of swell and wind-generated waves | m |
| SST (Sea Surface Temperature) | Temperature of water at the surface | °C |
WHO global UV index scale, used by IPMA.
| Level | Range | Advice |
|---|---|---|
| Low | 0–2 | No protection required. |
| Moderate | 3–5 | Protection recommended: hat, sunglasses, SPF 30+. |
| High | 6–7 | Avoid sun 11h-16h; SPF 30+, shade, clothing. |
| Very High | 8–10 | Extra protection; avoid being outside 11h-16h. |
| Extreme | 11+ | Stay indoors during midday; full protection outdoors. |
Status of harvesting availability in bivalve mollusc production zones. Note: Zones may have interdicted species even when the overall status is "open".
| Status | Description |
|---|---|
| Open | Harvesting permitted for all species. |
| Partially open | Harvesting permitted for some species; others interdicted. |
| Partially closed | Harvesting restricted; some species interdicted. |
| Closed | Harvesting prohibited for all species. |
| Unknown | Status not available. |
EU Sanitary Classification
Classifications follow EU bivalve sanitary standards:
- A: Ready for direct consumption
- B: Depuration required
- C: Relaying required
- NA: Not applicable