Snow Water Equivalent Dataset

375,923

Observations

847

Series

847

Subjects

1963–2026

Period covered

What this looks like

One real series from the dataset, and real rows from the head of its published extract. Neither is a mock-up: the rows below are the same rows, unchanged, that are in the file you would download.

Snow water equivalent at Lick Creek

The longest single series this dataset holds — 755 monthly values, one of 847. Drawn from 600 of them, evenly spaced across the record. The dataset is not this chart.

Drawn to show the shape and resolution of what the dataset contains, not to make a point about Lick Creek. Gaps are breaks, never interpolated.

View the data behind this chart

240 of 600 periods, evenly spaced across the record. Every value is in the download and the API; a table of all 600 would be longer than this page and unusable with a screen reader.
Period	Lick Creek (mm)
1963.75	0
1964.0833333333333	251
1964.25	486
1964.5833333333333	0
1964.8333333333333	46.8
1965.0833333333333	350
1965.3333333333333	200
1965.6666666666667	0
1965.8333333333333	18.8
1966.1666666666667	227
1966.3333333333333	18.8
1966.6666666666667	0
1966.9166666666667	89.3
1967.25	479
1967.4166666666667	0
1967.75	5.49
1967.9166666666667	164
1968.25	451
1968.5	0
1968.75	1.31
1969	170
1969.3333333333333	11.6
1969.5	0
1969.8333333333333	93.6
1970.0833333333333	298
1970.3333333333333	429
1970.5833333333333	0.492
1970.9166666666667	183
1971.0833333333333	335
1971.4166666666667	0
1971.5833333333333	0
1971.9166666666667	123
1972.1666666666667	261
1972.4166666666667	0
1972.6666666666667	0.169
1973	166
1973.1666666666667	285
1973.5	0
1973.75	6.39
1974	156
1974.25	426
1974.5833333333333	0
1974.75	4.18
1975.0833333333333	333
1975.25	558
1975.5833333333333	0
1975.8333333333333	79.4
1976.1666666666667	428
1976.3333333333333	140
1976.6666666666667	0
1976.8333333333333	44.0
1977.1666666666667	396
1977.4166666666667	0
1977.6666666666667	0
1977.9166666666667	94.1
1978.25	126
1978.4166666666667	0
1978.75	4.92
1979	167
1979.25	326
1979.5	0
1979.8333333333333	37.8
1980	160
1980.3333333333333	10.3
1980.5	0
1980.8333333333333	65.6
1981.0833333333333	213
1981.3333333333333	49.7
1981.5833333333333	0
1981.9166666666667	126
1982.0833333333333	239
1982.4166666666667	1.86
1982.6666666666667	0.593
1982.9166666666667	93.3
1983.1666666666667	239
1983.5	0
1983.6666666666667	2.03
1984	143
1984.1666666666667	295
1984.5	0
1984.8333333333333	51.9
1985.0833333333333	233
1985.3333333333333	0.082
1985.5833333333333	0
1985.9166666666667	96.7
1986.0833333333333	200
1986.4166666666667	0
1986.5833333333333	0
1986.9166666666667	113
1987.1666666666667	208
1987.4166666666667	0
1987.6666666666667	0
1988	129
1988.1666666666667	295
1988.5	0
1988.75	0.082
1989	149
1989.25	266
1989.5833333333333	0
1989.75	7.37
1990.0833333333333	226
1990.25	247
1990.5833333333333	0
1990.8333333333333	56.5
1991.1666666666667	274
1991.3333333333333	224
1991.6666666666667	1.52
1991.8333333333333	55.1
1992.1666666666667	211
1992.4166666666667	0.085
1992.6666666666667	0.254
1992.9166666666667	103
1993.25	258
1993.4166666666667	0
1993.75	4.10
1994	128
1994.25	214
1994.5	0.082
1994.8333333333333	73.5
1995	167
1995.3333333333333	234
1995.5	0
1995.8333333333333	60.5
1996.0833333333333	168
1996.3333333333333	166
1996.5833333333333	0
1996.9166666666667	163
1997.0833333333333	308
1997.4166666666667	0
1997.6666666666667	0.254
1997.9166666666667	49.3
1998.1666666666667	214
1998.5	0
1998.6666666666667	0
1999	128
1999.1666666666667	258
1999.5	0
1999.75	0
2000.0833333333333	149
2000.25	255
2000.5833333333333	0
2000.75	2.46
2001.0833333333333	153
2001.3333333333333	41.4
2001.5833333333333	0
2001.8333333333333	2.12
2002.1666666666667	211
2002.3333333333333	70.5
2002.6666666666667	0
2002.9166666666667	61.4
2003.1666666666667	281
2003.4166666666667	0
2003.75	1.72
2003.9166666666667	86.4
2004.25	168
2004.4166666666667	0
2004.75	5.82
2005	104
2005.25	231
2005.5	0
2005.8333333333333	57.6
2006.1666666666667	225
2006.3333333333333	49.5
2006.6666666666667	4.49
2006.8333333333333	50.0
2007.1666666666667	233
2007.4166666666667	1.86
2007.6666666666667	0
2007.9166666666667	54.1
2008.25	327
2008.4166666666667	7.54
2008.75	5.16
2009	128
2009.25	329
2009.5	0
2009.8333333333333	50.9
2010	114
2010.3333333333333	196
2010.5	0
2010.8333333333333	46.5
2011.0833333333333	202
2011.3333333333333	373
2011.5833333333333	0
2011.9166666666667	112
2012.0833333333333	211
2012.4166666666667	0
2012.6666666666667	0
2012.9166666666667	74.4
2013.1666666666667	219
2013.5	0
2013.6666666666667	0
2014	148
2014.1666666666667	333
2014.5	0
2014.75	0.246
2015.0833333333333	176
2015.25	196
2015.5833333333333	0
2015.75	0
2016.0833333333333	152
2016.3333333333333	55.8
2016.5833333333333	0
2016.8333333333333	16.6
2017.1666666666667	147
2017.3333333333333	63.5
2017.6666666666667	0.169
2017.9166666666667	112
2018.1666666666667	280
2018.4166666666667	0
2018.75	9.26
2018.9166666666667	88.2
2019.25	254
2019.4166666666667	0.593
2019.75	19.7
2020	124
2020.25	343
2020.5	0
2020.8333333333333	15.0
2021	99.1
2021.3333333333333	126
2021.5833333333333	0
2021.8333333333333	12.0
2022.0833333333333	134
2022.4166666666667	19.6
2022.5833333333333	0
2022.9166666666667	123
2023.0833333333333	225
2023.4166666666667	0
2023.6666666666667	0
2024	70.1
2024.1666666666667	168
2024.5	0
2024.6666666666667	0.169
2025	161
2025.25	304
2025.5	0
2025.75	5.16
2026.0833333333333	107
2026.25	56.6
2026.5833333333333	0.085

Sample rows

12 of 375,923 rows Taken from the start of observations-snow-ice-us-nrcs-snotel.csv. These are sample rows, not the dataset.

Sample rows from the Snow Water Equivalent Dataset extract
`metric_id`	`subject_id`	`subject_kind`	`value`	`censored`	`censor_operator`	`censor_threshold`	`censor_limit`	`censor_reported`	`unit`	`period_start`	`period_end`	`period_kind`	`basis`	`confidence`	`source_id`	`source_ref`	`qualifier`	`superseded`	`retrieved`
snow-water-equivalent	snotel-1000-or	geography	4.424516	—	—	—	—	—	mm	2000-10-01	2000-10-31	month	aggregated	high	us-nrcs-snotel	SNOTEL station 1000:OR:SNTL, snow water equivalent	—	—	2026-08-31
snow-water-equivalent	snotel-1000-or	geography	32.596667	—	—	—	—	—	mm	2000-11-01	2000-11-30	month	aggregated	high	us-nrcs-snotel	SNOTEL station 1000:OR:SNTL, snow water equivalent	—	—	2026-08-31
snow-water-equivalent	snotel-1000-or	geography	153.710968	—	—	—	—	—	mm	2000-12-01	2000-12-31	month	aggregated	high	us-nrcs-snotel	SNOTEL station 1000:OR:SNTL, snow water equivalent	—	—	2026-08-31
snow-water-equivalent	snotel-1000-or	geography	267.355484	—	—	—	—	—	mm	2001-01-01	2001-01-31	month	aggregated	high	us-nrcs-snotel	SNOTEL station 1000:OR:SNTL, snow water equivalent	—	—	2026-08-31
snow-water-equivalent	snotel-1000-or	geography	366.757857	—	—	—	—	—	mm	2001-02-01	2001-02-28	month	aggregated	high	us-nrcs-snotel	SNOTEL station 1000:OR:SNTL, snow water equivalent	—	—	2026-08-31
snow-water-equivalent	snotel-1000-or	geography	448.187097	—	—	—	—	—	mm	2001-03-01	2001-03-31	month	aggregated	high	us-nrcs-snotel	SNOTEL station 1000:OR:SNTL, snow water equivalent	—	—	2026-08-31
snow-water-equivalent	snotel-1000-or	geography	448.902667	—	—	—	—	—	mm	2001-04-01	2001-04-30	month	aggregated	high	us-nrcs-snotel	SNOTEL station 1000:OR:SNTL, snow water equivalent	—	—	2026-08-31
snow-water-equivalent	snotel-1000-or	geography	139.863871	—	—	—	—	—	mm	2001-05-01	2001-05-31	month	aggregated	high	us-nrcs-snotel	SNOTEL station 1000:OR:SNTL, snow water equivalent	—	—	2026-08-31
snow-water-equivalent	snotel-1000-or	geography	0	—	—	—	—	—	mm	2001-06-01	2001-06-30	month	aggregated	high	us-nrcs-snotel	SNOTEL station 1000:OR:SNTL, snow water equivalent	—	—	2026-08-31
snow-water-equivalent	snotel-1000-or	geography	0	—	—	—	—	—	mm	2001-07-01	2001-07-31	month	aggregated	high	us-nrcs-snotel	SNOTEL station 1000:OR:SNTL, snow water equivalent	—	—	2026-08-31
snow-water-equivalent	snotel-1000-or	geography	0	—	—	—	—	—	mm	2001-08-01	2001-08-31	month	aggregated	high	us-nrcs-snotel	SNOTEL station 1000:OR:SNTL, snow water equivalent	—	—	2026-08-31
snow-water-equivalent	snotel-1000-or	geography	0	—	—	—	—	—	mm	2001-09-01	2001-09-30	month	aggregated	high	us-nrcs-snotel	SNOTEL station 1000:OR:SNTL, snow water equivalent	—	—	2026-08-31

Download these rows as CSV — the same twelve, with the column header, for testing a loader before committing to the full file.

Methodology

Collected from the automated SNOTEL network, where each station weighs the snowpack on a pressure pillow every day. Hydrionis reduces the daily record to monthly means, as it does reservoir storage and for the same reason: snow water equivalent is a storage quantity, and what is held in the snowpack this month is the same kind of fact as what is held in the reservoir this month. A month is published only where the station reported on at least twenty of its days. Inches are converted to millimetres and the publisher unit is recorded alongside. The same service publishes a second network of manual snow courses whose records reach back to 1910; those are a different measurement — a person taking cores near the first of the month — and are deliberately not mixed into this record.

What this dataset cannot tell you

Read before relying on these figures

A value of zero is a measurement, not a gap: for most of these stations the snowpack is gone by July and the instrument reports that it is. Reading those months as absence would remove the very values that show when the melt finished.
This is a point measurement on a mountain, not a catchment average. A single pressure pillow can miss drifting and wind scour, and a station is not the snowpack of the basin around it.
Stations sit where snow reliably accumulates, which is high and often north-facing. The network describes mountain snowpack and not the lowlands the meltwater runs into.
Monthly means smooth a quantity that can change sharply in a warm week. The peak of a snowpack, and the date it melted out, are not recoverable from a monthly mean alone.
Coverage is the western United States and Alaska. There is no equivalent record here for the Alps or Fennoscandia, where Hydrionis holds its deepest river records.

Coverage

Subjects	Automated snow monitoring stations in the western United States and Alaska — 847 held
Period	1963–2026
Units	mm
Update cadence	Monthly
Identifier	`snow-water-equivalent` v1.0.0

Fields

Data dictionary →

Every metric this dataset carries, with the unit it is stored in and the geography level it is reported at. Full definitions are in the data dictionary.

Identifier	Field	Unit	Reported at
`snow-water-equivalent`	Snow water equivalent The depth of water that would result if a snowpack melted completely — the water actually stored as snow.	mm	monitoring-station, grid-cell

Rights and access

Licence position

Open. Derivative use true; redistribution true; commercial reuse true.

Applies to material authored by US federal agencies. Third-party material carried within a federal product may be separately protected.

Permitted uses

Public display
Derived analysis
API delivery
Bulk download
Commercial use

Available to: Public, Developer, Research, Professional, Enterprise. These follow from the rights of the contributing publishers, not from a Hydrionis pricing decision — no access tier can widen what a publisher withheld.

Contributing sources

United States Department of Agriculture, Natural Resources Conservation Service — SNOTEL and snow course network — snow water equivalent (US Government work — public domain)

Attribution and citation

Cite and reuse →

Two different obligations, deliberately kept apart. One is a condition of somebody else's licence; the other is a request Hydrionis has no standing to enforce.

Suggested citation for Hydrionis

Hydrionis (2026), Snow Water Equivalent Dataset, version 1.0.0, accessed 2026-09-02, hydrionis.com/data/datasets/snow-water-equivalent/

Cite Hydrionis where you rely on the compilation, the normalisation, the eligibility judgements or a chart. Where you use an unmodified published value, the publisher’s attribution is the one that is required; crediting Hydrionis as well is welcome and is not something Hydrionis can require of you.

Recommended, not required. Hydrionis does not claim rights over unmodified public data it relayed, and doing arithmetic on somebody else’s measurements does not make them Hydrionis’s. Cite the version and the access date: Snow Water Equivalent Dataset changes as publishers release and as methods are revised, and a citation without both cannot be checked later. Full guidance is on cite and reuse.

None of the contributing licences requires attribution. Crediting the publishers is still good practice and they are listed above.

Changelog

Version 1.0.0 — 2026-08-31

First release: the water in the snowpack, where Hydrionis previously held only its depth.

Additions

Monthly snow water equivalent for 847 stations, the earliest from 1963.

Use this data

Download snow-ice observations from NRCS (375,923 rows) (CSV)
Machine-readable JSON /api/v1/datasets/snow-water-equivalent.json
How to cite this, and who you must credit
How these figures were produced
Request this at a different scale, format or geography

Every bulk extract ships with a companion metadata file carrying this dataset’s version, its sources, their licences, the attribution you are required to give and the suggested citation — so the terms travel with the file rather than staying on this page.

About this data

The fields a professional user needs to judge whether this is fit for a particular purpose. Deliberately not a score.

About this data

Everything below is a property of the data rather than a rating of it. There is deliberately no single confidence score: how much a gap matters depends on what you are about to do with the series, and only you know that.

Source	United States Department of Agriculture, Natural Resources Conservation Service — SNOTEL and snow course network — snow water equivalent · US Government work — public domain
How the values came to exist	Mixed across the series — the basis is recorded on every individual value.
Period held	1963–2026
Known gaps	A value of zero is a measurement, not a gap: for most of these stations the snowpack is gone by July and the instrument reports that it is. Reading those months as absence would remove the very values that show when the melt finished. This is a point measurement on a mountain, not a catchment average. A single pressure pillow can miss drifting and wind scour, and a station is not the snowpack of the basin around it. Stations sit where snow reliably accumulates, which is high and often north-facing. The network describes mountain snowpack and not the lowlands the meltwater runs into.
Continuity	Version 1.0.0, released 2026-08-31. 1 recorded version; breaking changes and corrections are listed in the changelog above.
Last read from the publisher	2026-08-31 · publisher updates monthly
Redistribution	Permitted by the upstream licences
Commercial reuse	Permitted by the upstream licences. No Hydrionis access tier can widen this.
Methodology	How this was produced