{
 "source": "NOAA NCEI U.S. Climate Normals 1991-2020, freeze probabilities (our open release)",
 "method": "For every station with a median last-32F date, find the nearest other station and compare the two dates. Headline figures count a pair only when both stations have a complete 18-date record AND freeze in at least 90% of years. This is the error a nearest-station lookup inherits — a LOWER BOUND, since a real garden sits between stations, not on one.",
 "stations_with_dates": 6949,
 "pairs_measured": 6935,
 "pairs_full_record": 6191,
 "pairs_marginal_excluded_from_headline": 744,
 "marginal_note": "Pairs are excluded from every headline number unless BOTH stations have a full 18-date record AND freeze in at least 90% of years. Where frost is irregular, a median last-frost date is a median over years that include no frost at all — unstable, and not something a gardener can act on.",
 "sensitivity": {
  "note": "Same computation under the looser filter (complete record only, no frost-frequency bar). Published so the headline cannot be mistaken for an artifact of where we chose to draw the line.",
  "headline_filter": {
   "label": "record complete AND frost in 90%+ of years",
   "pairs": 6191,
   "medianMiles": 10.5,
   "medianDayDiff": 5,
   "p90DayDiff": 16,
   "worstDayDiff": 114,
   "shareOver7": 40.2,
   "shareOver14": 13.8,
   "shareOver21": 5.3
  },
  "record_complete_only": {
   "label": "record complete only",
   "pairs": 6380,
   "medianMiles": 10.4,
   "medianDayDiff": 5,
   "p90DayDiff": 16,
   "worstDayDiff": 126,
   "shareOver7": 41.1,
   "shareOver14": 14.8,
   "shareOver21": 6
  }
 },
 "overall": {
  "medianDayDiff": 5,
  "p90DayDiff": 16,
  "p99DayDiff": 39,
  "worstDayDiff": 114,
  "shareOver7": 40.2,
  "shareOver14": 13.8,
  "shareOver21": 5.3
 },
 "byDistance": [
  {
   "label": "within 10 miles",
   "pairs": 2966,
   "medianMiles": 5.3,
   "medianDayDiff": 5,
   "p90DayDiff": 15,
   "worstDayDiff": 114,
   "shareOver7": 38.2,
   "shareOver14": 13.1,
   "shareOver21": 4.6
  },
  {
   "label": "within 25 miles",
   "pairs": 6030,
   "medianMiles": 10.2,
   "medianDayDiff": 5,
   "p90DayDiff": 15,
   "worstDayDiff": 114,
   "shareOver7": 39.6,
   "shareOver14": 13.4,
   "shareOver21": 5
  },
  {
   "label": "within 50 miles",
   "pairs": 6189,
   "medianMiles": 10.5,
   "medianDayDiff": 5,
   "p90DayDiff": 16,
   "worstDayDiff": 114,
   "shareOver7": 40.2,
   "shareOver14": 13.8,
   "shareOver21": 5.3
  },
  {
   "label": "within 100 miles",
   "pairs": 6191,
   "medianMiles": 10.5,
   "medianDayDiff": 5,
   "p90DayDiff": 16,
   "worstDayDiff": 114,
   "shareOver7": 40.2,
   "shareOver14": 13.8,
   "shareOver21": 5.3
  }
 ],
 "worstNeighbours": [
  {
   "a": "BRIGHT ANGEL RS, AZ US",
   "b": "PHANTOM RCH, AZ US",
   "miles": 7.7,
   "daysApart": 114,
   "elevDiffM": 1667
  },
  {
   "a": "BALCH PWR HOUSE, CA US",
   "b": "GRANT GROVE, CA US",
   "miles": 13.8,
   "daysApart": 98,
   "elevDiffM": 1477
  },
  {
   "a": "GRAND CANYON E ENTRANCE, AZ US",
   "b": "PHANTOM RCH, AZ US",
   "miles": 15.6,
   "daysApart": 90,
   "elevDiffM": 1509
  },
  {
   "a": "COALINGA, CA US",
   "b": "PRIEST VALLEY, CA US",
   "miles": 19,
   "daysApart": 83,
   "elevDiffM": 497
  },
  {
   "a": "PHANTOM RCH, AZ US",
   "b": "GRAND CANYON VISITOR CTR, AZ US",
   "miles": 3.4,
   "daysApart": 82,
   "elevDiffM": 1388
  },
  {
   "a": "NEW CUYAMA FIRE STN, CA US",
   "b": "TAFT, CA US",
   "miles": 20.1,
   "daysApart": 81,
   "elevDiffM": 423
  },
  {
   "a": "MT CHARLESTON FIRE STN, NV US",
   "b": "RED ROCK CANYON - SPG MT RCH S, NV US",
   "miles": 16.8,
   "daysApart": 79,
   "elevDiffM": 1122
  },
  {
   "a": "CALAVERAS BIG TREES, CA US",
   "b": "NEW MELONES DAM HQ, CA US",
   "miles": 21.1,
   "daysApart": 76,
   "elevDiffM": 1138
  },
  {
   "a": "DE SABLA, CA US",
   "b": "PARADISE, CA US",
   "miles": 8.2,
   "daysApart": 69,
   "elevDiffM": 293
  },
  {
   "a": "LAKE ARROWHEAD, CA US",
   "b": "HESPERIA 2E, CA US",
   "miles": 12.8,
   "daysApart": 66,
   "elevDiffM": 655
  },
  {
   "a": "FT BRAGG 5 N, CA US",
   "b": "WILLITS 1 NE, CA US",
   "miles": 22.9,
   "daysApart": 64,
   "elevDiffM": 375
  },
  {
   "a": "PORTLAND-HILLSBORO AP, OR US",
   "b": "NATURE PARK-BEAVERTON, OR US",
   "miles": 6,
   "daysApart": 64,
   "elevDiffM": 6
  },
  {
   "a": "ANGWIN PACIFIC UNION COLLEGE, CA US",
   "b": "SAINT HELENA, CA US",
   "miles": 4.9,
   "daysApart": 63,
   "elevDiffM": 454
  },
  {
   "a": "PAHRUMP 4 NW, NV US",
   "b": "MT CHARLESTON FIRE STN, NV US",
   "miles": 22.9,
   "daysApart": 63,
   "elevDiffM": 1490
  },
  {
   "a": "COUGAR DAM, OR US",
   "b": "MCKENZIE RVR RS, OR US",
   "miles": 7.1,
   "daysApart": 60,
   "elevDiffM": 67
  }
 ],
 "closeButWrong": [
  {
   "a": "BRIGHT ANGEL RS, AZ US",
   "b": "PHANTOM RCH, AZ US",
   "miles": 7.7,
   "daysApart": 114,
   "elevDiffM": 1667
  },
  {
   "a": "BALCH PWR HOUSE, CA US",
   "b": "GRANT GROVE, CA US",
   "miles": 13.8,
   "daysApart": 98,
   "elevDiffM": 1477
  },
  {
   "a": "PHANTOM RCH, AZ US",
   "b": "GRAND CANYON VISITOR CTR, AZ US",
   "miles": 3.4,
   "daysApart": 82,
   "elevDiffM": 1388
  },
  {
   "a": "DE SABLA, CA US",
   "b": "PARADISE, CA US",
   "miles": 8.2,
   "daysApart": 69,
   "elevDiffM": 293
  },
  {
   "a": "LAKE ARROWHEAD, CA US",
   "b": "HESPERIA 2E, CA US",
   "miles": 12.8,
   "daysApart": 66,
   "elevDiffM": 655
  },
  {
   "a": "PORTLAND-HILLSBORO AP, OR US",
   "b": "NATURE PARK-BEAVERTON, OR US",
   "miles": 6,
   "daysApart": 64,
   "elevDiffM": 6
  },
  {
   "a": "ANGWIN PACIFIC UNION COLLEGE, CA US",
   "b": "SAINT HELENA, CA US",
   "miles": 4.9,
   "daysApart": 63,
   "elevDiffM": 454
  },
  {
   "a": "COUGAR DAM, OR US",
   "b": "MCKENZIE RVR RS, OR US",
   "miles": 7.1,
   "daysApart": 60,
   "elevDiffM": 67
  },
  {
   "a": "MUND'S PARK, AZ US",
   "b": "OAK CREEK CANYON, AZ US",
   "miles": 6.8,
   "daysApart": 57,
   "elevDiffM": 412
  },
  {
   "a": "BEN LOMOND #4, CA US",
   "b": "SANTA CRUZ, CA US",
   "miles": 8.1,
   "daysApart": 55,
   "elevDiffM": 107
  },
  {
   "a": "HOLLISTER 2, CA US",
   "b": "PAICINES 4 W, CA US",
   "miles": 10,
   "daysApart": 54,
   "elevDiffM": 192
  },
  {
   "a": "MAPLETON, OR US",
   "b": "FLORENCE #2, OR US",
   "miles": 11.7,
   "daysApart": 54,
   "elevDiffM": 18
  }
 ],
 "flatGround": [
  {
   "a": "PORTLAND-HILLSBORO AP, OR US",
   "b": "NATURE PARK-BEAVERTON, OR US",
   "miles": 6,
   "daysApart": 64,
   "elevDiffM": 6
  },
  {
   "a": "MAPLETON, OR US",
   "b": "FLORENCE #2, OR US",
   "miles": 11.7,
   "daysApart": 54,
   "elevDiffM": 18
  },
  {
   "a": "YACHATS, OR US",
   "b": "ALSEA FH (FALL CREEK), OR US",
   "miles": 17.8,
   "daysApart": 53,
   "elevDiffM": 55
  },
  {
   "a": "NORTH BEND RGNL AP, OR US",
   "b": "COOS BAY 8 SW, OR US",
   "miles": 10.5,
   "daysApart": 53,
   "elevDiffM": 2
  },
  {
   "a": "SEQUIM 2 E, WA US",
   "b": "PORT TOWNSEND, WA US",
   "miles": 14.3,
   "daysApart": 51,
   "elevDiffM": 15
  },
  {
   "a": "BEAVERTON 2 SSW, OR US",
   "b": "NATURE PARK-BEAVERTON, OR US",
   "miles": 3.1,
   "daysApart": 49,
   "elevDiffM": 26
  },
  {
   "a": "LACOMB 3 NNE, OR US",
   "b": "LEBANON, OR US",
   "miles": 11,
   "daysApart": 43,
   "elevDiffM": 58
  },
  {
   "a": "TRACY CARBONA, CA US",
   "b": "TRACY PUMPING PLT, CA US",
   "miles": 15.1,
   "daysApart": 37,
   "elevDiffM": 23
  },
  {
   "a": "BANDON 2 NNE, OR US",
   "b": "COOS BAY 8 SW, OR US",
   "miles": 9.4,
   "daysApart": 37,
   "elevDiffM": 3
  },
  {
   "a": "SULLIVANS IS, SC US",
   "b": "CHARLESTON CITY, SC US",
   "miles": 4.5,
   "daysApart": 37,
   "elevDiffM": 2
  }
 ]
}