Castle Airport (KMER), California
Landing essentials
Whether you can land, whether you can refuel, and how customs works here.
Overview
Castle Airport (KMER) sits in Atwater, California, on the site of a former Air Force base, which explains its 11,802-foot runway and its continued use by civilian and military training traffic. The airport is towered and operates on a Monday-through-Friday schedule from 0800 to 1700 local. Jet A and 100LL are both available onsite. Customs is not offered at the field itself; the nearest customs facility is KFAT, about 54.5 nm away. Business aviation activity places KMER in Skystar's second traffic tier, with FAA TFMSC data showing 419 annual bizav operations against 1,563 total operations in 2025.
Runways
Castle Airport has one paved runway, 13/31, 11,802 ft long and 150 ft wide, with an asphalt and concrete surface.
Runway geometry from published threshold coordinates. Not for navigation.
Source: FAA Form 5010.
Fuel and airfield services
Castle Airport has Jet A, Jet A1 and 100LL available on the field. Fueling is available from 8am to 5pm, daily, and the airport has an operating control tower.
Source: FAA Form 5010 / NASR.
Customs
Castle Airport does not clear customs. The nearest port of entry is Fresno Yosemite International (KFAT), 55 NM away.
Source: CBP list of ports of entry.
Business aviation traffic
Castle Airport recorded 419 business aviation movements in 2025. Traffic peaks in January, July and September. Business aviation traffic at KMER peaks in January, July, and September, with the lowest activity recorded in February.
Business jet movements, FAA TFMSC count. Peak month September, 44 movements in 2025.
Source: FAA TFMSC, business jet movements, 2025.
Climate
Castle Airport averages 28.1 days above 90°F in July and 9.4 freeze days in December. July is the warmest month, with average highs of 94.8°F, and January the coldest, at 54.1°F.
Weather station is 6.0 NM from the field. Some values are estimated by the agency. 1991–2020 climate normals.
Source: NOAA NCEI.
Operating constraints
Castle Airport has published operating constraints in four categories: access, weight restrictions, runway notes and other notes.
For clearance delivery when the control tower is closed, contact NorCal Approach.
Taxiway B is closed to aircraft greater than 30,000 pounds.
When the control tower is closed, activate ALSF1 on runways 13 and 31; HIRL for runway 13/31 is available on CTAF using 3 clicks for on, 5 clicks to increase intensity, and 7 clicks for off. PAPI on runways 13 and 31 operates continuously.
A 1,000-foot paved blast pad is present on both ends of the runway.
180-degree turns are prohibited on runway 13/31.
Runway 31 is the designated calm wind runway, used when winds are 5 knots or less.
The opposite end of the runway is not visible on takeoff. When the control tower is closed, opposite-direction takeoffs and landings are not authorized.
Fuel is available from 1800 to 0900.
For airport information, contact the extension listed for airport operations.
Civilian and military training activity may occasionally cause pattern congestion.
When the control tower is closed, a maximum of 5 aircraft is permitted in the VFR traffic pattern at any one time, with a 2,000-foot ceiling and 3 miles visibility recommended.
Source: FAA Chart Supplement.
Nearby airfields
Castle Airport has five airfields within 33 NM. The closest is Merced Yosemite Regional (KMCE), 6.30 NM southeast.
Part of the California Central Valley area.
Source: Skystar calculation from official coordinates.
Skystar at KMER
We arrange catering, fuel and trip support here. Supplier prices reach you unchanged; our coordination fee sits on its own line.
The same order, priced two ways.
$1,200.00 catering order at KMER.
Unchanged.
What the kitchen invoices us is what your quote reads.
One line, fixed.
It does not move with the size of the order.
At cost.
Passed on at the exact amount the processor took.
Market practice figures are industry averages, not a specific competitor.
Frequently asked questions
What runway does KMER offer for larger business aircraft?
Castle Airport (KMER) has a single runway, 13/31, measuring 11,802 feet long and 150 feet wide with an asphalt-concrete surface. This length accommodates large aircraft operations, and a 1,000-foot paved blast pad is present on both ends of the runway. The runway also carries the airport's maximum paved length designation, making it the field's only paved surface.
Is fuel available around the clock at KMER?
Fuel at Castle Airport (KMER) is limited to certain hours rather than continuous service. Per the airport's remarks, fuel is available from 1800 to 0900 local time. Both Jet A and 100LL are stocked at the field, but dispatchers should plan arrivals around this window rather than assuming daytime availability.
Can aircraft use KMER when the tower is closed?
Operations at Castle Airport (KMER) are restricted when the control tower is closed. Opposite-direction takeoffs and landings are not authorized during those hours because the opposite end of the runway is not visible on takeoff. A maximum of five aircraft is permitted in the VFR traffic pattern at any one time, with a 2,000-foot ceiling and 3 miles visibility recommended.
Are there any taxiway weight restrictions at KMER?
Yes, Taxiway B at Castle Airport (KMER) is closed to aircraft exceeding 30,000 pounds. Dispatchers planning heavier aircraft movements should account for this restriction when coordinating ground routing. This limitation is separate from the runway itself, which supports substantially heavier operations given its length and pavement classification.