Carlsbad Caverns Visitor Center
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Carlsbad Caverns Visitor Center clear sky chart from 2005-11-06 to 2024-04-10.

This page is a summary of past forecasts. Even though it's based only on forecasts, some people use these pages as clue to a site's climate. But climate data based on actual observation should be preferred (if you can find it!).

Cloud, Transparency and Seeing forecasts are summarized individually. But because good observing conditions require a combination of minimum cloud cover, transparency and seeing, the individual forecast summaries can be difficult to interpret. The observing conditions section counts the combinations of conditions needed for common types of astronomical observation.

Observing Conditions

The following tables count the occurrence of the combinations of forecast and darkness conditions needed for different observations. Conditions are rated by by what percentage of the hours the observation would likely be attempted are usable.

Observation Type	Minimum conditions for hour to be usable				Out of hours
	Clear of Clouds	Transparency	Seeing	Sky Brightness
Planetary:	50%	(no limit)	Average	(no limit)	Nighttime Hours
Deep Sky:	70%	Average	(no limit)	5.9	Nighttime Hours
CCD Imaging:	70%	Below Average	Poor	(no limit)	Nighttime Hours

Percentages are of nighttime hours per month, or per year, when a particular observing conditions was met. Deep Sky percentages never exceed 50% because the moon is up half the time. Deep sky percentages are much lower for charts at high latitudes because of fewer dark hours in the summer.

Overall

By Month

Individual Forecasts

The length of each colored bar in the "occurrence of each Forecast" column is proportional to the number of times the chart forecast that color. The percentages are of the total number of hours per month, or per year, with a particular forecast. The colors as the same as those used in clear sky charts.

Note: Transparency probabilities are only counted for those hours that have 30% or less cloud cover. Seeing probabilities are only counted for those hours that have 80% or less cloud cover. If that's too tricky, try Observing Conditions instead.

Overall

		Occurrence of each Forecast	Data Points
Cloud Cover	Day	5% 3 1 3 3 2 3 4 5% 8% 63%	83710
	Night	5% 3 1 3 3 2 3 4 5% 7% 64%	85121
Transparency	Day	19% 5% 9% 17% 26% 24%	83449
	Night	19% 5% 8% 16% 26% 26%	84906
Seeing	Day	6% 8% 22% 31% 24% 8%	13976
	Night	6% 7% 26% 38% 21% 2	24239

By Month

Percentage Cloud Cover SW (2006-)
Color Meanings: Overcast 90% covered 80% covered 70% covered 60% covered 50% covered 40% covered 30% covered 20% covered 10% covered Clear
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	3 4 2 3 2 2 3 2 4 6% 70%	2858
	11th to 20th	Day	2 2 1 2 3 2 3 3 3 5% 73%	2860
	21st to end	Day	4 5% 2 4 4 2 4 4 4 8% 60%	3437
February	1st to 10th	Day	2 3 2 4 2 2 3 4 4 6% 69%	1900
	11th to 20th	Day	3 6% 2 4 3 2 3 4 4 7% 61%	1849
	21st to end	Day	2 4 2 3 4 2 3 3 3 5% 70%	1570
March	1st to 10th	Day	3 3 2 4 4 2 3 4 5% 7% 62%	3130
	11th to 20th	Day	12% 6% 2 3 4 3 3 3 4 6% 53%	3453
	21st to end	Day	2 3 2 4 4 3 4 5% 6% 8% 59%	4089
April	1st to 10th	Day	3 3 1 2 2 2 3 4 5% 7% 69%	2269
	11th to 20th	Day	5% 2 1 2 2 2 3 2 3 5% 73%	2131
	21st to end	Day	2 1 1 2 3 1 3 3 4 6% 74%	2160
May	1st to 10th	Day	4 2 1 2 3 2 2 4 4 6% 71%	2160
	11th to 20th	Day	6% 3 1 3 3 2 3 4 5% 7% 64%	2133
	21st to end	Day	4 2 1 2 2 2 3 4 5% 6% 68%	2531
June	1st to 10th	Day	2 2 1 2 3 2 3 5% 7% 9% 67%	2360
	11th to 20th	Day	2 2 1 3 3 2 3 5% 5% 9% 67%	2520
	21st to end	Day	5% 3 1 3 4 2 4 4 6% 9% 59%	2520
July	1st to 10th	Day	5% 3 1 4 4 2 6% 7% 7% 13% 47%	2427
	11th to 20th	Day	5% 2 2 3 3 2 4 6% 7% 11% 54%	2340
	21st to end	Day	5% 2 2 3 4 2 4 5% 6% 11% 54%	2349
August	1st to 10th	Day	4 1 1 2 4 3 5% 6% 8% 12% 54%	2149
	11th to 20th	Day	4 4 2 4 4 3 6% 6% 9% 11% 46%	2123
	21st to end	Day	6% 3 1 4 4 3 5% 7% 9% 11% 48%	2376
September	1st to 10th	Day	9% 3 1 3 5% 3 4 5% 7% 8% 52%	2160
	11th to 20th	Day	10% 4 2 4 5% 3 5% 5% 6% 8% 49%	2088
	21st to end	Day	8% 2 1 2 3 2 3 3 4 6% 66%	1980
October	1st to 10th	Day	6% 3 1 3 3 2 3 3 5% 8% 63%	1954
	11th to 20th	Day	6% 3 1 2 3 1 2 2 3 4 72%	1800
	21st to end	Day	4 3 1 2 3 2 2 2 2 4 76%	1980
November	1st to 10th	Day	6% 2 1 2 2 1 2 3 3 5% 72%	1783
	11th to 20th	Day	3 3 1 3 3 2 3 4 4 5% 69%	1710
	21st to end	Day	5% 3 1 2 3 1 3 4 5% 6% 65%	1710
December	1st to 10th	Day	6% 4 2 4 3 2 3 4 5% 6% 61%	1710
	11th to 20th	Day	2 3 2 3 3 2 4 5% 7% 8% 61%	2161
	21st to end	Day	3 3 1 3 2 2 2 3 3 6% 71%	2980
January	1st to 10th	Night	3 4 1 3 4 2 3 4 4 6% 67%	4097
	11th to 20th	Night	3 3 1 3 3 2 3 3 3 7% 70%	4110
	21st to end	Night	5% 4 2 4 4 2 3 4 5% 8% 59%	4211
February	1st to 10th	Night	3 4 1 3 2 2 3 3 4 7% 69%	2280
	11th to 20th	Night	5% 3 2 3 3 2 3 3 4 6% 64%	2218
	21st to end	Night	5% 3 1 3 3 2 3 3 4 6% 66%	1884
March	1st to 10th	Night	4 4 1 3 4 2 3 3 4 6% 66%	3734
	11th to 20th	Night	15% 4 2 3 4 3 4 5% 5% 6% 51%	3522
	21st to end	Night	2 3 1 4 3 2 4 5% 5% 7% 64%	3553
April	1st to 10th	Night	3 3 1 3 4 2 3 3 4 6% 68%	1900
	11th to 20th	Night	5% 2 2 2 3 2 2 4 4 5% 70%	1777
	21st to end	Night	3 2 1 2 2 1 3 2 3 5% 76%	1800
May	1st to 10th	Night	4 2 1 2 3 2 3 3 4 6% 71%	1800
	11th to 20th	Night	7% 2 2 2 3 2 3 3 5% 7% 64%	1757
	21st to end	Night	4 1 1 2 2 2 3 4 5% 8% 67%	1745
June	1st to 10th	Night	3 2 1 3 3 2 4 5% 8% 9% 60%	1594
	11th to 20th	Night	2 1 1 3 3 2 3 3 5% 8% 68%	1440
	21st to end	Night	4 2 1 3 3 2 4 4 7% 10% 60%	1440
July	1st to 10th	Night	5% 2 1 4 4 3 4 5% 8% 12% 52%	1527
	11th to 20th	Night	3 2 2 3 4 3 5% 6% 8% 12% 53%	1620
	21st to end	Night	5% 2 2 4 3 2 5% 7% 8% 12% 50%	1964
August	1st to 10th	Night	3 2 1 3 4 3 6% 4 8% 14% 52%	1790
	11th to 20th	Night	4 3 1 4 4 3 5% 6% 8% 13% 49%	1778
	21st to end	Night	4 3 2 4 4 3 4 8% 7% 11% 49%	1980
September	1st to 10th	Night	7% 3 2 3 4 3 4 6% 6% 8% 55%	1800
	11th to 20th	Night	8% 3 2 4 3 3 4 4 7% 9% 52%	1871
	21st to end	Night	6% 3 1 3 3 2 3 4 6% 7% 62%	1980
October	1st to 10th	Night	7% 3 1 3 3 2 3 4 4 6% 65%	2002
	11th to 20th	Night	7% 3 1 2 2 1 2 2 3 4 72%	2160
	21st to end	Night	5% 3 1 2 2 1 2 3 3 4 73%	2376
November	1st to 10th	Night	5% 2 1 1 2 1 2 2 3 5% 74%	2274
	11th to 20th	Night	2 3 1 2 3 2 3 4 4 6% 71%	2470
	21st to end	Night	6% 3 1 3 2 1 3 3 4 5% 67%	2470
December	1st to 10th	Night	7% 4 1 3 3 2 3 4 4 8% 61%	2470
	11th to 20th	Night	3 3 1 4 3 3 3 4 4 7% 64%	3036
	21st to end	Night	2 3 1 2 2 2 3 3 3 5% 73%	4691

Transparency (when cloud cover <= 30%)
Color Meanings: Too cloudy to forecast Poor Below Average Average Above average Transparent
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	16% 3 6% 11% 34% 30%	2859
	11th to 20th	Day	12% 4 6% 15% 39% 24%	2860
	21st to end	Day	21% 5% 8% 21% 28% 17%	3437
February	1st to 10th	Day	17% 3 7% 15% 25% 33%	1900
	11th to 20th	Day	23% 4 7% 14% 23% 30%	1859
	21st to end	Day	18% 4 4 10% 25% 40%	1570
March	1st to 10th	Day	19% 4 7% 10% 27% 33%	3130
	11th to 20th	Day	30% 5% 7% 13% 25% 21%	3453
	21st to end	Day	16% 5% 9% 12% 27% 31%	4089
April	1st to 10th	Day	15% 3 6% 11% 28% 36%	2269
	11th to 20th	Day	16% 3 4 10% 25% 41%	2134
	21st to end	Day	12% 3 6% 12% 30% 38%	2160
May	1st to 10th	Day	15% 3 5% 10% 23% 44%	2160
	11th to 20th	Day	21% 4 8% 14% 25% 28%	2136
	21st to end	Day	16% 5% 8% 18% 17% 37%	2531
June	1st to 10th	Day	13% 6% 10% 21% 24% 25%	2360
	11th to 20th	Day	14% 4 7% 15% 22% 38%	2520
	21st to end	Day	21% 6% 10% 18% 25% 21%	2520
July	1st to 10th	Day	25% 10% 16% 23% 20% 6%	2363
	11th to 20th	Day	19% 9% 14% 22% 24% 11%	2271
	21st to end	Day	21% 9% 18% 31% 19% 3	2219
August	1st to 10th	Day	19% 8% 16% 31% 22% 4	2136
	11th to 20th	Day	27% 9% 20% 24% 15% 4	2123
	21st to end	Day	26% 11% 17% 23% 17% 7%	2376
September	1st to 10th	Day	27% 8% 13% 18% 19% 15%	2160
	11th to 20th	Day	30% 7% 11% 17% 23% 11%	2088
	21st to end	Day	20% 5% 7% 17% 32% 19%	1980
October	1st to 10th	Day	20% 6% 11% 16% 24% 23%	1954
	11th to 20th	Day	19% 3 5% 13% 27% 33%	1800
	21st to end	Day	15% 3 4 17% 32% 30%	1980
November	1st to 10th	Day	16% 3 5% 18% 29% 29%	1783
	11th to 20th	Day	17% 5% 7% 17% 28% 26%	1710
	21st to end	Day	20% 4 7% 15% 28% 26%	1710
December	1st to 10th	Day	23% 5% 7% 20% 29% 16%	1710
	11th to 20th	Day	19% 6% 10% 18% 26% 20%	2159
	21st to end	Day	15% 4 6% 18% 32% 26%	2980
January	1st to 10th	Night	16% 4 8% 11% 35% 26%	4097
	11th to 20th	Night	15% 4 8% 15% 33% 25%	4110
	21st to end	Night	22% 5% 7% 20% 29% 17%	4211
February	1st to 10th	Night	15% 4 8% 14% 24% 35%	2280
	11th to 20th	Night	21% 5% 8% 11% 25% 32%	2218
	21st to end	Night	18% 4 5% 10% 21% 42%	1884
March	1st to 10th	Night	18% 4 5% 9% 23% 40%	3734
	11th to 20th	Night	31% 7% 7% 11% 23% 22%	3522
	21st to end	Night	14% 6% 8% 11% 29% 32%	3553
April	1st to 10th	Night	18% 3 5% 11% 24% 39%	1900
	11th to 20th	Night	16% 4 7% 12% 21% 39%	1777
	21st to end	Night	13% 3 4 14% 27% 39%	1800
May	1st to 10th	Night	16% 4 5% 10% 20% 45%	1800
	11th to 20th	Night	20% 5% 8% 14% 23% 30%	1758
	21st to end	Night	15% 7% 10% 15% 19% 34%	1746
June	1st to 10th	Night	18% 7% 12% 18% 22% 23%	1594
	11th to 20th	Night	15% 4 8% 14% 23% 37%	1440
	21st to end	Night	18% 6% 16% 19% 22% 19%	1440
July	1st to 10th	Night	21% 9% 17% 25% 22% 5%	1483
	11th to 20th	Night	19% 10% 15% 21% 24% 11%	1566
	21st to end	Night	22% 10% 17% 28% 21% 4	1855
August	1st to 10th	Night	21% 6% 13% 31% 23% 6%	1779
	11th to 20th	Night	24% 8% 19% 27% 17% 5%	1778
	21st to end	Night	26% 9% 14% 25% 19% 8%	1980
September	1st to 10th	Night	26% 8% 12% 18% 19% 18%	1800
	11th to 20th	Night	26% 7% 13% 21% 20% 13%	1871
	21st to end	Night	22% 6% 9% 17% 28% 19%	1980
October	1st to 10th	Night	21% 5% 9% 16% 23% 26%	2002
	11th to 20th	Night	18% 3 5% 14% 26% 34%	2160
	21st to end	Night	17% 2 5% 14% 29% 33%	2376
November	1st to 10th	Night	14% 3 5% 15% 30% 33%	2274
	11th to 20th	Night	15% 3 6% 17% 30% 30%	2470
	21st to end	Night	20% 4 6% 15% 28% 27%	2470
December	1st to 10th	Night	22% 4 6% 18% 25% 24%	2470
	11th to 20th	Night	20% 3 6% 19% 29% 23%	3037
	21st to end	Night	14% 4 6% 13% 36% 27%	4691

Seeing (when cloud cover <= 80%)
Color Meanings: Too cloudy to forecast Bad 1/5 Poor 2/5 Average 3/5 Good 4/5 Excellent 5/5
Month	Days in Month		Occurrence of each Forecast	Data Points
January	1st to 10th	Day	9% 14% 33% 34% 10%	270
	11th to 20th	Day	10% 14% 33% 32% 11% 1	270
	21st to end	Day	3 13% 33% 37% 12% 1	297
February	1st to 10th	Day	4 14% 34% 33% 13% 2	270
	11th to 20th	Day	11% 13% 36% 30% 9% 1	270
	21st to end	Day	8% 22% 34% 28% 7% 1	225
March	1st to 10th	Day	10% 13% 37% 31% 8% 1	270
	11th to 20th	Day	13% 15% 33% 28% 9% 2	436
	21st to end	Day	6% 25% 40% 23% 6% 1	506
April	1st to 10th	Day	7% 19% 37% 29% 7% 1	457
	11th to 20th	Day	5% 24% 37% 25% 7% 1	412
	21st to end	Day	5% 16% 40% 27% 11% 1	420
May	1st to 10th	Day	4 14% 39% 31% 11%	423
	11th to 20th	Day	6% 9% 30% 34% 17% 3	456
	21st to end	Day	6% 5% 30% 41% 18% 1	679
June	1st to 10th	Day	3 2 17% 44% 31% 3	630
	11th to 20th	Day	2 3 18% 40% 32% 6%	630
	21st to end	Day	5% 1 12% 34% 38% 9%	630
July	1st to 10th	Day	5% 6% 26% 46% 17%	533
	11th to 20th	Day	3 3 27% 42% 25%	444
	21st to end	Day	2 1 2 28% 44% 24%	487
August	1st to 10th	Day	3 4 21% 46% 26%	447
	11th to 20th	Day	4 2 7% 26% 42% 19%	437
	21st to end	Day	5% 1 6% 22% 40% 26%	495
September	1st to 10th	Day	8% 1 8% 30% 38% 16%	450
	11th to 20th	Day	5% 1 6% 30% 44% 15%	378
	21st to end	Day	8% 1 10% 27% 35% 18%	270
October	1st to 10th	Day	11% 3 16% 28% 34% 8%	270
	11th to 20th	Day	9% 4 17% 35% 27% 7%	270
	21st to end	Day	7% 8% 25% 27% 24% 9%	297
November	1st to 10th	Day	12% 8% 27% 29% 20% 4	270
	11th to 20th	Day	5% 11% 22% 34% 23% 5%	270
	21st to end	Day	10% 14% 33% 27% 13% 3	270
December	1st to 10th	Day	13% 13% 20% 37% 16% 2	270
	11th to 20th	Day	4 16% 26% 40% 13%	270
	21st to end	Day	7% 14% 35% 32% 10% 1	297
January	1st to 10th	Night	8% 9% 32% 37% 13% 1	760
	11th to 20th	Night	7% 9% 37% 34% 11% 2	760
	21st to end	Night	6% 10% 35% 38% 11% 1	836
February	1st to 10th	Night	5% 12% 36% 34% 12% 1	760
	11th to 20th	Night	8% 10% 37% 37% 6% 1	744
	21st to end	Night	6% 18% 43% 27% 6%	628
March	1st to 10th	Night	8% 12% 37% 35% 8% 1	760
	11th to 20th	Night	10% 13% 29% 34% 13%	760
	21st to end	Night	3 13% 44% 33% 6%	677
April	1st to 10th	Night	4 13% 42% 36% 5%	570
	11th to 20th	Night	5% 11% 42% 35% 6%	533
	21st to end	Night	2 11% 44% 34% 8%	540
May	1st to 10th	Night	4 5% 43% 41% 7%	540
	11th to 20th	Night	7% 5% 29% 44% 15%	531
	21st to end	Night	5% 4 28% 51% 12%	584
June	1st to 10th	Night	2 3 19% 54% 20% 1	540
	11th to 20th	Night	2 1 20% 56% 20%	540
	21st to end	Night	4 1 13% 52% 30% 1	540
July	1st to 10th	Night	5% 7% 42% 43% 3	525
	11th to 20th	Night	3 5% 40% 49% 3	522
	21st to end	Night	4 1 5% 32% 54% 5%	591
August	1st to 10th	Night	4 4 26% 62% 5%	537
	11th to 20th	Night	4 4 25% 58% 8%	534
	21st to end	Night	6% 1 4 29% 55% 6%	594
September	1st to 10th	Night	8% 1 5% 36% 45% 6%	540
	11th to 20th	Night	8% 1 4 40% 45% 3	540
	21st to end	Night	8% 1 9% 42% 36% 4	540
October	1st to 10th	Night	9% 2 17% 45% 25% 2	562
	11th to 20th	Night	8% 5% 18% 44% 22% 3	720
	21st to end	Night	6% 7% 21% 35% 25% 6%	792
November	1st to 10th	Night	7% 4 23% 39% 25% 3	794
	11th to 20th	Night	4 6% 25% 43% 20% 2	950
	21st to end	Night	8% 10% 28% 35% 16% 2	950
December	1st to 10th	Night	9% 8% 30% 36% 15% 1	950
	11th to 20th	Night	6% 10% 35% 36% 11% 1	950
	21st to end	Night	5% 13% 36% 36% 9% 1	1045

Page generated at 2024-04-07 07:28:11. Version ac07

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