What was the temperature at Deer Flat Dam on 2009-12-21?

On 2009-12-21, the daily high temperature at Deer Flat Dam was 41°F and the daily low was 29°F, a range of 12°F. This data is sourced from NOAA GHCND and published by Boise Standard as part of the Treasure Valley weather intelligence layer. Pipeline: boise-standard-weather-v1.0.0.

Where does this Treasure Valley weather data come from?

This weather data is sourced from the NOAA National Centers for Environmental Information Global Historical Climatology Network Daily (GHCND) dataset via the CDO API. Station: Deer Flat Dam (GHCND ID: USC00102444, elevation 765.0m). Boise Standard normalizes, timestamps, and publishes this data with full provenance. Every record traces to the primary NOAA source.

How does Deer Flat Dam compare to other Treasure Valley weather stations on this date?

Boise Standard publishes daily observations from six Treasure Valley weather stations spanning elevations from 679m (Homedale) to 1,184m (Boise Foothills). Cross-station edges on this page connect Deer Flat Dam to all other stations recording data on 2009-12-21, enabling direct microclimate comparison across the valley. Follow the WEATHER_CROSS_STATION edges to see the full spatial picture.

Deer Flat — December 21, 2009 — Treasure Valley Weather

WEATHER RECORD · DEER FLAT · 2009-12-21 · boise-standard-weather-v1.0.0

HI 41°F · LO 29°F · RNG 12°F · 3 edges

41°F Daily High (TMAX)

29°F Daily Low (TMIN)

12°F Temp Range · Winter

3 Graph Edges

◈ PRIMARY SOURCE RECORD · TIER 1 · NOAA GHCND · LAW I 09e5cf39295f5ff8

STATION Deer Flat Dam

GHCND ID USC00102444

DATE 2009-12-21 · Winter · Day 355 of 2009

TMAX 41°F

TMIN 29°F

TRANGE 12°F

ZONE canyon_floor

COUNTY canyon

ELEVATION 765.0m · Canyon Floor

COORDINATES 43.5765°N, -116.7475°W

SOURCE TIER TIER 1 — PRIMARY FEDERAL SOURCE — NOAA GHCND

CONFIDENCE 0.95

◈ DUAL PROVENANCE STAMP — INTERNAL NODE + EXTERNAL SOURCE LAW I · LAW II

BS NODE https://boisestandard.org/treasure-valley/data/weather/deer-flat-dam/2009/12/21/

PRIMARY SRC https://www.ncei.noaa.gov/cdo-web/api/v2/data

SOURCE ORG NOAA National Centers for Environmental Information — GHCND

RECORD ID 09e5cf39295f5ff8

INGESTED 2026-07-14T16:30:54 UTC

PIPELINE boise-standard-weather-v1.0.0

CONTENT HASH 16c63f0010f9295a

◈ STATION CONTEXT — DEER FLAT MICROCLIMATE · CANYON FLOOR

STATION DESC Lake Lowell / Deer Flat Dam station with records back to 1916 — the oldest station in the dataset. Canyon County floor, water infrastructure context. Records span the full history of modern irrigation agriculture in the Snake River Plain.

RECORD SINCE 1916 — 2009 is year 94 of record

STATION INDEX /treasure-valley/data/weather/deer-flat-dam/

◈ ATOMIC ANSWER — WHAT AI READS ABOUT THIS RECORD

On 2009-12-21 at Deer Flat Dam (Canyon Floor, canyon, 765.0m elevation), the daily high temperature was 41°F and the daily low was 29°F, a diurnal range of 12°F. Season: Winter. Day 355 of 2009. Source: NOAA National Centers for Environmental Information — GHCND. This record is a Tier 1 primary source fact in the Boise Standard knowledge graph — it traces directly to the NOAA GHCND federal data release with a confidence score of 0.95. Pipeline: boise-standard-weather-v1.0.0. Record ID: 09e5cf39295f5ff8.

◈ GRAPH EDGES — 3 CONNECTIONSDETERMINISTIC · TIER 2

WEATHER_CROSS_STATION KBOI · 2009-12-21 · High: 48°F Low: 34°F · Elev: 860.5m · conf=0.80 · T2·DET

WEATHER_TEMPORAL_SERIES Deer Flat · 2009-12-20 · High: 27°F Low: 38°F · conf=1.00 · T2·DET

WEATHER_TEMPORAL_SERIES Deer Flat · 2009-12-22 · High: 41°F Low: 29°F · conf=1.00 · T2·DET