KMER Castle

PROBABLE 68%

Runway 31 — local convention slightly favors it

No D-ATIS feed here — a voice ATIS/AWOS may exist; check the frequency. ADS-B tracking just started here — traffic history is still building. Weather observation is 10546 minutes old — treat with caution.

certainty: 68% evidence: NONE Class D

Wind 320° true at 6 kt · VFR · 10546 min old

▶ Listen live — ATIS/CTAF on LiveATC opens LiveATC’s own player · verify the broadcast yourself

31 62% 11802 ft · 6 kt head, 0 kt x-left · right traffic · calm-wind rwy

13 38% 11802 ft · 6 kt TAIL, 0 kt x-right

Active NOTAMs affecting runways

LIGHTING RWY 31 until 03-29 21:11Z

RWY 31 SEQUENCED FLG LGT U/S

APCH OTS RWY 31 until 10-18 23:59Z

NAV ILS RWY 31 GP U/S

Why — evidence behind this answer

Runway 31

PRIOR 31 is the designated calm-wind runway +0.50
WIND 6 kt headwind, 0 kt left crosswind 10546 min ago +0.00

Runway 13

WIND 6 kt TAILWIND, 0 kt right crosswind 10546 min ago -0.00

Sources consulted

source	status	age	note
D_ATIS	UNAVAILABLE		No D-ATIS at this field
METAR	OK	10546 min
ADSB	WARMING_UP	1744 min	Only 0 min of track history so far
NOTAM	OK
CIFP	NOT_CONFIGURED		Instrument procedures: phase 4

Recent operations

No operations observed in the last hour. (Only 0 min of track history so far)

Was this right?

KMER field & runways

Castle, Atwater, California. Field elevation 190 ft. Class D airspace. Towered. Magnetic variation 15.0°E on record, 12.4°E today.

The FAA's variation of record is the number this field was surveyed against; the second is where north points now, from WMM2025. It is moving 0.088°/year west — about 1° every 11 years — which is why runway numbers eventually stop matching their pavement.

Runway data from the FAA NASR 01 Oct 2026 cycle. Where NASR locates both thresholds, the true heading is the bearing between them rather than NASR's whole-degree alignment. Magnetic is that heading against *today's* declination from WMM2025, not the field's variation of record — so it can differ from the chart by the gap between the two shown above. The number painted on the runway is the one ATC uses.
Runway	True	Magnetic	Number	Length	Surface	Pattern	Notes
13	141.2°	128.7°	matches	11,802 ft	ASPH-CONC
31	321.2°	308.7°	matches	11,802 ft	ASPH-CONC	right	ILS calm-wind RY 31 WILL BE THE DESIGNATED CALM WIND RY (WIND 5 KNOTS OR LESS).

Generated 08:41:19Z · auto-refreshes · JSON

KMER ☆ Castle