Mjøsa Lake
Mjøsa Lake in Unknown, Norway has official water-quality measurements, not a LakeQuality A–F grade. Water clarity: 9 m visibility. Phosphorus: 4.6 µg/L. Chlorophyll-a (algae): 2.1 µg/L.
- Clarity
- 9 m
Why Mjøsa Lake has no A–F grade
Mjøsa Lake in Norway is published with the authority's own measurements, not a LakeQuality letter. official authority class; not a LakeQuality A–F letter Sampling here has recorded water clarity, phosphorus and algae (chlorophyll-a).
A letter on the LakeQuality scale would be an invention, not an official class. Everything below that has been measured is still reported on this page.
Monitoring: the Norwegian Environment Agency, via UNEP GEMS/Water (OPEN GFQA).
Mjøsa Lake is a lake in Unknown County, Norway.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2023-10-30. Grade methodology: LakeGrade methodology.
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Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Mjøsa Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Crystal clear, you can see 29.5 ft down. Phosphorus level: 4.6 µg/L. Chlorophyll-a: 2.1 µg/L. Trophic State Index: 31.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 9 m | Not graded |
| Phosphorus | 4.6 µg/L | Not graded |
| Chlorophyll-a (Algae) | 2.1 µg/L | Not graded |
| Trophic State Index (TSI) | 31 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay near Mjøsa Lake
Compare lakeside cabins, hotels, and vacation rentals near Mjøsa Lake in Unknown, Norway — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water.
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Fishing Mjøsa Lake
Frequently asked questions about Mjøsa Lake
What is the water quality of Mjøsa Lake?
- Mjøsa Lake in Unknown, Norway has official water-quality measurements, not a LakeQuality A–F grade. Water clarity: 9 m visibility. Phosphorus: 4.6 µg/L. Chlorophyll-a (algae): 2.1 µg/L.
Is Mjøsa Lake safe to swim in?
- Mjøsa Lake has official nutrient and clarity measurements, not a bacteria swim class and not a safety clearance. Algal blooms, currents, and depth are not covered. Always check local notices before swimming.
Explore Mjøsa Lake across LakeGrade
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Where this data comes from
233 measurements from 1 monitoring station, 2016–2023. Retrieved from UNEP GEMS/Water GFQA (not the EPA Water Quality Portal) on 2026-08-16.
Collected and reported by
- European Environment Agency
europeanenvironmentagenc233 samples · —
Analytical methods
- GEMStat OPEN / CC BY 4.0
Monitoring station identifiers (1)
NOR00019
Authority classifications are stored separately from LakeQuality A–F letters and are never blended. See methodology and data sources.
Data Sources
Water quality data from the EPA Water Quality Portal
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion
Most recent sample: 2023-10-30
Monitoring stations: 1