Lava Beds National Monument
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Lava Beds National Monument clear sky chart from 2005-11-06 to 2026-02-16.

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	3 5% 2 5% 4 4 4 4 6% 7% 57%	139994
	Night	3 5% 2 5% 4 4 4 4 6% 7% 56%	138247
Transparency	Day	26% 8% 10% 20% 21% 15%	134864
	Night	27% 9% 11% 21% 20% 12%	134367
Seeing	Day	8% 13% 21% 26% 22% 9%	16440
	Night	7% 9% 22% 36% 23% 3	25712

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 8% 3 9% 7% 6% 7% 6% 8% 11% 33%	4722
	11th to 20th	Day	4 6% 2 6% 4 4 3 3 5% 7% 55%	4856
	21st to end	Day	3 5% 2 6% 5% 5% 5% 5% 7% 8% 48%	5843
February	1st to 10th	Day	3 9% 3 7% 5% 6% 5% 5% 7% 10% 42%	1890
	11th to 20th	Day	3 7% 2 8% 5% 5% 6% 5% 8% 9% 42%	1843
	21st to end	Day	2 8% 3 7% 7% 7% 6% 5% 6% 9% 40%	1650
March	1st to 10th	Day	3 9% 4 9% 6% 6% 6% 5% 8% 9% 36%	4648
	11th to 20th	Day	2 8% 2 6% 5% 5% 5% 4 7% 7% 48%	5000
	21st to end	Day	3 9% 4 10% 6% 6% 6% 4 7% 9% 36%	5693
April	1st to 10th	Day	5% 8% 3 9% 6% 6% 6% 4 7% 8% 38%	2400
	11th to 20th	Day	6% 7% 3 7% 5% 5% 5% 4 6% 9% 45%	2369
	21st to end	Day	4 6% 2 6% 5% 5% 4 3 6% 9% 49%	2400
May	1st to 10th	Day	3 5% 2 4 3 3 3 3 4 6% 64%	6089
	11th to 20th	Day	3 4 1 4 3 4 4 3 5% 7% 62%	6277
	21st to end	Day	3 3 1 4 3 3 3 3 5% 9% 63%	6902
June	1st to 10th	Day	6% 5% 2 5% 5% 4 5% 4 7% 8% 49%	2800
	11th to 20th	Day	3 3 1 4 3 4 4 3 5% 7% 64%	2800
	21st to end	Day	3 2 1 3 2 2 2 3 4 5% 72%	2800
July	1st to 10th	Day	1 1 1 2 2 2 3 2 3 4 79%	6319
	11th to 20th	Day	1 2 1 3 2 2 2 3 4 4 76%	6320
	21st to end	Day	2 2 1 4 3 3 4 3 5% 6% 67%	6717
August	1st to 10th	Day	1 2 1 3 2 3 4 4 7% 8% 66%	5777
	11th to 20th	Day	1 1 2 2 2 3 3 4 6% 77%	5664
	21st to end	Day	2 2 1 2 2 2 3 2 4 6% 74%	5984
September	1st to 10th	Day	1 1 1 2 2 2 2 3 5% 80%	2400
	11th to 20th	Day	3 2 1 3 3 3 3 4 5% 5% 67%	2400
	21st to end	Day	3 3 1 4 2 2 2 3 4 6% 70%	2138
October	1st to 10th	Day	3 3 1 3 2 2 3 2 3 5% 73%	3280
	11th to 20th	Day	3 3 1 4 3 3 4 3 6% 8% 62%	3261
	21st to end	Day	4 6% 2 5% 4 5% 5% 4 7% 9% 50%	3527
November	1st to 10th	Day	6% 7% 3 7% 5% 4 5% 4 6% 9% 44%	1854
	11th to 20th	Day	5% 7% 2 8% 6% 5% 5% 6% 8% 10% 37%	1791
	21st to end	Day	3 5% 2 7% 6% 6% 5% 5% 7% 10% 45%	1680
December	1st to 10th	Day	2 4 1 5% 4 5% 5% 4 6% 11% 52%	2700
	11th to 20th	Day	5% 11% 4 9% 6% 7% 6% 6% 7% 10% 28%	3108
	21st to end	Day	4 8% 3 10% 7% 7% 7% 6% 9% 12% 27%	4092
January	1st to 10th	Night	3 7% 3 8% 6% 7% 8% 6% 9% 11% 33%	8172
	11th to 20th	Night	2 5% 2 4 3 3 4 3 5% 7% 63%	8106
	21st to end	Night	5% 8% 3 7% 5% 6% 6% 4 6% 7% 44%	8371
February	1st to 10th	Night	3 6% 3 8% 6% 5% 5% 5% 8% 9% 44%	2730
	11th to 20th	Night	4 7% 2 6% 5% 5% 6% 5% 7% 8% 44%	2553
	21st to end	Night	2 6% 3 7% 6% 6% 7% 5% 8% 10% 41%	1980
March	1st to 10th	Night	3 8% 4 7% 5% 5% 6% 5% 8% 10% 38%	5244
	11th to 20th	Night	2 6% 2 5% 5% 4 5% 4 8% 9% 51%	5000
	21st to end	Night	2 8% 3 9% 7% 7% 7% 5% 8% 9% 36%	5281
April	1st to 10th	Night	4 8% 3 6% 6% 5% 6% 5% 7% 9% 42%	2000
	11th to 20th	Night	4 8% 2 6% 4 3 5% 3 5% 7% 52%	1979
	21st to end	Night	6% 7% 2 6% 4 3 4 3 5% 8% 52%	2000
May	1st to 10th	Night	3 4 2 4 3 3 2 3 4 7% 66%	3879
	11th to 20th	Night	3 4 1 4 3 3 3 3 5% 6% 65%	3616
	21st to end	Night	3 3 1 3 2 3 3 2 4 6% 71%	3972
June	1st to 10th	Night	6% 5% 2 6% 4 4 3 5% 6% 7% 54%	1600
	11th to 20th	Night	4 2 1 3 2 4 3 3 4 5% 68%	1600
	21st to end	Night	3 1 1 3 2 2 2 3 4 5% 75%	1600
July	1st to 10th	Night	1 1 3 2 2 2 2 3 3 81%	3640
	11th to 20th	Night	1 2 1 2 2 1 2 2 3 4 81%	3640
	21st to end	Night	2 2 1 3 3 3 4 3 5% 6% 71%	4137
August	1st to 10th	Night	1 1 2 2 2 3 2 5% 6% 75%	4035
	11th to 20th	Night	2 1 1 1 1 1 2 3 4 83%	4190
	21st to end	Night	2 3 1 2 2 2 2 2 3 4 77%	5015
September	1st to 10th	Night	2 1 2 1 1 2 2 3 4 82%	2000
	11th to 20th	Night	3 3 1 3 2 2 3 3 4 6% 70%	2000
	21st to end	Night	2 3 1 3 2 3 3 3 5% 7% 70%	2257
October	1st to 10th	Night	2 3 1 2 2 2 3 3 3 4 77%	3920
	11th to 20th	Night	4 4 1 4 3 2 3 3 4 6% 67%	3897
	21st to end	Night	2 4 1 4 4 4 5% 4 7% 9% 56%	4281
November	1st to 10th	Night	5% 7% 2 6% 5% 5% 4 5% 7% 9% 45%	2665
	11th to 20th	Night	6% 7% 2 7% 5% 5% 6% 5% 8% 10% 41%	2825
	21st to end	Night	2 6% 3 6% 5% 5% 4 5% 6% 9% 49%	2940
December	1st to 10th	Night	2 4 1 4 4 4 4 4 7% 10% 57%	4700
	11th to 20th	Night	6% 9% 3 8% 6% 6% 7% 6% 7% 10% 32%	5316
	21st to end	Night	5% 10% 3 9% 6% 6% 5% 5% 7% 10% 35%	7106

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	43% 14% 14% 20% 9%	4723
	11th to 20th	Day	31% 6% 7% 15% 20% 22%	4856
	21st to end	Day	33% 10% 11% 14% 16% 16%	5843
February	1st to 10th	Day	39% 11% 13% 21% 13% 3	1890
	11th to 20th	Day	38% 14% 13% 20% 13% 2	1852
	21st to end	Day	42% 11% 15% 16% 12% 5%	1650
March	1st to 10th	Day	43% 15% 9% 19% 11% 4	4648
	11th to 20th	Day	33% 10% 12% 24% 20% 1	5000
	21st to end	Day	43% 11% 15% 20% 10% 1	5693
April	1st to 10th	Day	45% 9% 14% 17% 13% 2	2400
	11th to 20th	Day	36% 8% 12% 24% 15% 4	2372
	21st to end	Day	34% 8% 14% 25% 18% 2	2400
May	1st to 10th	Day	21% 7% 8% 25% 32% 7%	6089
	11th to 20th	Day	19% 7% 10% 24% 32% 8%	6280
	21st to end	Day	19% 7% 12% 34% 25% 3	6904
June	1st to 10th	Day	31% 7% 13% 25% 20% 4	2800
	11th to 20th	Day	20% 6% 10% 25% 31% 9%	2800
	21st to end	Day	14% 4 6% 22% 32% 22%	2800
July	1st to 10th	Day	10% 4 4 12% 20% 50%	6251
	11th to 20th	Day	10% 3 4 10% 22% 50%	6245
	21st to end	Day	16% 5% 6% 18% 24% 31%	6521
August	1st to 10th	Day	15% 4 5% 12% 19% 45%	4206
	11th to 20th	Day	8% 3 6% 16% 41% 26%	4099
	21st to end	Day	10% 3 5% 21% 34% 28%	4311
September	1st to 10th	Day	9% 2 5% 14% 28% 41%	2400
	11th to 20th	Day	18% 5% 8% 18% 32% 18%	2400
	21st to end	Day	17% 5% 9% 21% 29% 20%	2138
October	1st to 10th	Day	17% 3 8% 15% 28% 30%	3280
	11th to 20th	Day	19% 7% 9% 32% 27% 6%	3261
	21st to end	Day	27% 11% 12% 24% 20% 7%	3527
November	1st to 10th	Day	38% 9% 13% 19% 16% 4	1854
	11th to 20th	Day	40% 13% 14% 18% 14% 2	1791
	21st to end	Day	35% 11% 11% 20% 16% 6%	1680
December	1st to 10th	Day	27% 9% 8% 22% 24% 10%	2700
	11th to 20th	Day	49% 12% 16% 15% 7% 1	3108
	21st to end	Day	43% 17% 14% 17% 7% 1	4092
January	1st to 10th	Night	39% 16% 17% 21% 7% 1	8172
	11th to 20th	Night	25% 8% 8% 14% 19% 25%	8106
	21st to end	Night	38% 11% 7% 12% 21% 11%	8371
February	1st to 10th	Night	36% 11% 14% 21% 14% 4	2730
	11th to 20th	Night	36% 13% 14% 20% 14% 3	2555
	21st to end	Night	38% 12% 16% 17% 13% 4	1980
March	1st to 10th	Night	39% 15% 10% 20% 12% 4	5244
	11th to 20th	Night	27% 12% 14% 25% 21%	5000
	21st to end	Night	39% 16% 17% 20% 8%	5281
April	1st to 10th	Night	39% 12% 17% 20% 11% 2	2000
	11th to 20th	Night	31% 10% 17% 23% 14% 5%	1979
	21st to end	Night	30% 8% 19% 27% 13% 2	2000
May	1st to 10th	Night	20% 7% 10% 28% 30% 4	3876
	11th to 20th	Night	20% 8% 12% 28% 26% 6%	3616
	21st to end	Night	17% 6% 14% 40% 21% 1	3972
June	1st to 10th	Night	29% 7% 17% 30% 14% 2	1600
	11th to 20th	Night	19% 5% 10% 31% 28% 7%	1600
	21st to end	Night	14% 3 8% 26% 35% 14%	1600
July	1st to 10th	Night	9% 3 5% 15% 22% 46%	3600
	11th to 20th	Night	9% 2 4 10% 25% 50%	3592
	21st to end	Night	14% 5% 7% 23% 24% 27%	4021
August	1st to 10th	Night	13% 3 5% 16% 21% 43%	2929
	11th to 20th	Night	6% 2 5% 21% 42% 23%	3028
	21st to end	Night	10% 2 4 30% 27% 26%	3608
September	1st to 10th	Night	9% 2 5% 15% 27% 41%	2000
	11th to 20th	Night	16% 5% 8% 23% 29% 19%	2000
	21st to end	Night	16% 5% 9% 22% 25% 23%	2257
October	1st to 10th	Night	14% 4 7% 15% 33% 28%	3920
	11th to 20th	Night	20% 6% 9% 35% 23% 7%	3897
	21st to end	Night	22% 11% 11% 25% 24% 8%	4281
November	1st to 10th	Night	37% 10% 13% 19% 16% 5%	2665
	11th to 20th	Night	38% 12% 14% 18% 14% 3	2825
	21st to end	Night	33% 11% 14% 17% 18% 7%	2940
December	1st to 10th	Night	24% 8% 9% 20% 28% 10%	4700
	11th to 20th	Night	44% 15% 12% 18% 9% 1	5316
	21st to end	Night	43% 14% 16% 18% 9% 1	7106

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	15% 22% 28% 25% 8% 2	220
	11th to 20th	Day	13% 19% 19% 21% 16% 11%	258
	21st to end	Day	8% 15% 22% 26% 20% 8%	473
February	1st to 10th	Day	12% 19% 21% 23% 19% 6%	430
	11th to 20th	Day	11% 22% 23% 26% 15% 3	433
	21st to end	Day	9% 19% 28% 25% 17% 2	414
March	1st to 10th	Day	13% 27% 29% 18% 12% 1	500
	11th to 20th	Day	14% 20% 25% 23% 16% 2	500
	21st to end	Day	16% 23% 25% 22% 12% 2	550
April	1st to 10th	Day	11% 24% 25% 24% 12% 4	500
	11th to 20th	Day	13% 20% 23% 24% 13% 7%	492
	21st to end	Day	5% 19% 26% 25% 17% 8%	500
May	1st to 10th	Day	10% 16% 29% 24% 17% 4	503
	11th to 20th	Day	12% 16% 23% 24% 15% 9%	528
	21st to end	Day	9% 11% 20% 26% 22% 11%	573
June	1st to 10th	Day	7% 12% 18% 25% 25% 13%	530
	11th to 20th	Day	6% 15% 25% 24% 21% 8%	530
	21st to end	Day	2 7% 18% 29% 28% 15%	530
July	1st to 10th	Day	3 4 19% 35% 27% 13%	526
	11th to 20th	Day	1 2 18% 31% 34% 14%	524
	21st to end	Day	2 3 13% 30% 34% 17%	575
August	1st to 10th	Day	2 1 18% 31% 31% 17%	527
	11th to 20th	Day	1 5% 16% 29% 30% 19%	517
	21st to end	Day	2 4 18% 29% 31% 16%	583
September	1st to 10th	Day	1 5% 19% 28% 34% 13%	530
	11th to 20th	Day	5% 7% 19% 29% 26% 13%	530
	21st to end	Day	5% 8% 20% 27% 30% 9%	530
October	1st to 10th	Day	8% 10% 20% 25% 25% 12%	530
	11th to 20th	Day	6% 15% 15% 26% 28% 10%	530
	21st to end	Day	8% 15% 20% 27% 20% 10%	564
November	1st to 10th	Day	11% 16% 19% 29% 19% 7%	330
	11th to 20th	Day	12% 13% 19% 26% 24% 5%	278
	21st to end	Day	9% 9% 20% 25% 30% 6%	220
December	1st to 10th	Day	9% 14% 19% 29% 19% 10%	220
	11th to 20th	Day	15% 20% 16% 23% 17% 9%	220
	21st to end	Day	14% 19% 24% 23% 19% 1	242
January	1st to 10th	Night	11% 13% 28% 29% 16% 3	840
	11th to 20th	Night	6% 16% 23% 30% 21% 3	840
	21st to end	Night	8% 10% 26% 33% 19% 3	924
February	1st to 10th	Night	7% 10% 28% 35% 18% 1	840
	11th to 20th	Night	9% 14% 25% 34% 17% 2	804
	21st to end	Night	5% 16% 29% 36% 13% 2	660
March	1st to 10th	Night	10% 17% 30% 27% 14% 3	800
	11th to 20th	Night	10% 13% 24% 33% 17% 2	800
	21st to end	Night	8% 18% 30% 30% 14%	880
April	1st to 10th	Night	8% 12% 30% 35% 14% 2	800
	11th to 20th	Night	8% 11% 31% 30% 18% 3	791
	21st to end	Night	9% 10% 26% 34% 19% 2	800
May	1st to 10th	Night	6% 8% 29% 34% 20% 1	509
	11th to 20th	Night	11% 6% 25% 36% 21% 2	394
	21st to end	Night	10% 6% 24% 38% 22% 1	433
June	1st to 10th	Night	7% 6% 19% 43% 25% 1	400
	11th to 20th	Night	5% 6% 28% 45% 17% 1	400
	21st to end	Night	4 1 14% 54% 27% 1	400
July	1st to 10th	Night	2 1 13% 53% 31% 1	390
	11th to 20th	Night	1 12% 57% 29%	388
	21st to end	Night	1 5% 51% 39% 4	504
August	1st to 10th	Night	1 6% 43% 46% 3	597
	11th to 20th	Night	1 1 8% 45% 40% 4	654
	21st to end	Night	2 2 12% 42% 38% 3	880
September	1st to 10th	Night	2 2 13% 42% 38% 3	800
	11th to 20th	Night	5% 3 15% 36% 37% 6%	800
	21st to end	Night	4 4 16% 37% 33% 6%	800
October	1st to 10th	Night	5% 4 22% 35% 30% 5%	800
	11th to 20th	Night	5% 7% 17% 35% 32% 5%	800
	21st to end	Night	7% 8% 18% 36% 26% 6%	880
November	1st to 10th	Night	10% 10% 20% 36% 20% 5%	820
	11th to 20th	Night	11% 13% 23% 32% 18% 3	840
	21st to end	Night	6% 13% 20% 33% 24% 3	840
December	1st to 10th	Night	9% 10% 23% 32% 23% 3	840
	11th to 20th	Night	10% 18% 20% 32% 17% 3	840
	21st to end	Night	12% 18% 28% 32% 9% 1	924

Page generated at 2026-02-12 22:42:13. Version ac07

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