Espanola
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Espanola clear sky chart from 2005-11-06 to 2024-12-06.

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	16% 10% 4 8% 5% 4 4 3 5% 6% 35%	101865
	Night	15% 11% 4 8% 5% 4 4 3 5% 6% 34%	97933
Transparency	Day	48% 6% 13% 21% 11% 1	105377
	Night	49% 7% 13% 20% 10% 1	102509
Seeing	Day	22% 16% 32% 20% 7% 2	15404
	Night	21% 13% 31% 26% 9% 1	24640

By Month

Percentage Cloud Cover NE (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	16% 20% 8% 13% 4 3 3 2 3 5% 22%	2208
	11th to 20th	Day	11% 13% 6% 18% 9% 5% 5% 4 5% 5% 18%	2466
	21st to end	Day	16% 24% 8% 12% 6% 4 4 4 4 4 15%	2935
February	1st to 10th	Day	10% 17% 6% 11% 7% 6% 5% 4 4 5% 25%	1710
	11th to 20th	Day	12% 16% 5% 11% 6% 4 4 4 4 5% 29%	1663
	21st to end	Day	11% 17% 5% 14% 7% 5% 4 3 4 5% 25%	1532
March	1st to 10th	Day	17% 14% 3 7% 4 4 4 3 6% 6% 32%	3267
	11th to 20th	Day	11% 14% 5% 10% 5% 4 4 3 5% 7% 32%	3480
	21st to end	Day	13% 14% 7% 8% 5% 4 4 2 4 5% 34%	3815
April	1st to 10th	Day	17% 15% 4 7% 5% 4 5% 3 4 6% 29%	2242
	11th to 20th	Day	20% 11% 3 6% 4 4 4 4 5% 6% 35%	2442
	21st to end	Day	22% 9% 3 7% 4 4 3 3 5% 6% 36%	2470
May	1st to 10th	Day	18% 7% 3 7% 5% 4 4 3 5% 7% 37%	4108
	11th to 20th	Day	13% 9% 2 6% 5% 4 4 4 5% 7% 42%	4320
	21st to end	Day	17% 7% 2 5% 4 4 4 2 5% 6% 44%	5043
June	1st to 10th	Day	16% 7% 3 7% 5% 4 5% 4 6% 7% 37%	2850
	11th to 20th	Day	13% 6% 2 6% 5% 4 5% 4 6% 7% 40%	2850
	21st to end	Day	17% 7% 3 7% 5% 5% 5% 4 6% 7% 36%	2850
July	1st to 10th	Day	17% 8% 3 7% 5% 4 4 3 6% 8% 35%	4760
	11th to 20th	Day	11% 4 2 6% 4 5% 5% 4 5% 8% 45%	4760
	21st to end	Day	11% 5% 2 5% 4 4 4 4 5% 8% 49%	4696
August	1st to 10th	Day	11% 6% 2 7% 4 5% 6% 4 6% 8% 40%	4104
	11th to 20th	Day	17% 5% 2 5% 3 4 4 4 5% 8% 41%	4044
	21st to end	Day	13% 5% 2 5% 4 4 4 3 6% 7% 45%	4532
September	1st to 10th	Day	14% 7% 3 7% 4 3 5% 4 6% 7% 40%	2266
	11th to 20th	Day	14% 5% 2 6% 4 4 5% 4 5% 7% 45%	2090
	21st to end	Day	21% 8% 3 7% 5% 4 4 3 3 6% 37%	2090
October	1st to 10th	Day	20% 8% 3 6% 5% 4 4 3 5% 6% 37%	1943
	11th to 20th	Day	24% 9% 3 8% 5% 4 6% 3 5% 7% 25%	1900
	21st to end	Day	26% 13% 3 8% 4 4 3 3 6% 6% 24%	1943
November	1st to 10th	Day	19% 12% 3 8% 5% 5% 3 3 5% 7% 29%	1695
	11th to 20th	Day	17% 16% 4 9% 5% 5% 5% 3 4 5% 25%	1600
	21st to end	Day	20% 21% 5% 10% 6% 4 3 3 3 4 20%	1600
December	1st to 10th	Day	12% 23% 6% 9% 5% 4 4 4 5% 5% 22%	1489
	11th to 20th	Day	18% 17% 6% 9% 6% 4 3 4 4 5% 24%	1671
	21st to end	Day	26% 21% 6% 10% 4 3 3 2 3 4 17%	2431
January	1st to 10th	Night	15% 16% 8% 12% 6% 4 4 3 5% 6% 22%	4748
	11th to 20th	Night	12% 14% 5% 13% 7% 5% 5% 4 6% 6% 23%	4500
	21st to end	Night	15% 20% 7% 11% 6% 5% 4 4 5% 4 19%	4724
February	1st to 10th	Night	12% 15% 5% 12% 6% 5% 5% 4 5% 6% 25%	2470
	11th to 20th	Night	11% 14% 5% 10% 7% 4 5% 4 5% 6% 29%	2403
	21st to end	Night	12% 17% 5% 9% 6% 5% 5% 4 5% 7% 26%	1918
March	1st to 10th	Night	16% 12% 3 8% 5% 4 4 3 4 6% 36%	3573
	11th to 20th	Night	10% 12% 5% 9% 5% 4 4 4 5% 6% 36%	3479
	21st to end	Night	13% 9% 8% 8% 5% 4 4 3 4 6% 36%	3817
April	1st to 10th	Night	19% 10% 3 7% 5% 5% 4 3 5% 5% 34%	1953
	11th to 20th	Night	19% 9% 3 6% 4 3 4 3 5% 5% 38%	1687
	21st to end	Night	20% 9% 3 8% 5% 4 4 4 4 5% 34%	1710
May	1st to 10th	Night	17% 7% 3 8% 5% 4 4 4 5% 6% 37%	2833
	11th to 20th	Night	10% 8% 3 6% 5% 5% 6% 3 6% 8% 40%	2571
	21st to end	Night	13% 8% 2 6% 4 4 4 3 5% 8% 42%	2537
June	1st to 10th	Night	12% 7% 2 8% 5% 5% 5% 5% 7% 8% 37%	1330
	11th to 20th	Night	11% 6% 3 6% 4 4 5% 4 6% 9% 42%	1330
	21st to end	Night	14% 5% 3 7% 4 4 4 3 6% 8% 41%	1330
July	1st to 10th	Night	15% 7% 2 5% 4 4 4 3 5% 7% 44%	2210
	11th to 20th	Night	11% 5% 2 4 4 4 4 3 5% 7% 50%	2210
	21st to end	Night	10% 5% 2 5% 4 4 4 3 5% 8% 51%	2857
August	1st to 10th	Night	10% 6% 2 6% 4 5% 4 5% 7% 7% 44%	2825
	11th to 20th	Night	14% 5% 2 6% 4 3 4 3 6% 7% 46%	2785
	21st to end	Night	11% 4 2 5% 4 3 4 4 5% 7% 51%	3124
September	1st to 10th	Night	14% 7% 2 6% 4 4 4 3 6% 7% 45%	1893
	11th to 20th	Night	12% 4 2 4 4 3 3 3 4 8% 53%	2090
	21st to end	Night	17% 8% 3 6% 4 4 3 3 5% 6% 40%	2090
October	1st to 10th	Night	21% 7% 3 6% 4 4 4 3 4 7% 39%	2237
	11th to 20th	Night	24% 10% 3 7% 4 3 4 3 4 6% 31%	2280
	21st to end	Night	25% 11% 3 7% 5% 4 4 3 5% 5% 27%	2653
November	1st to 10th	Night	18% 12% 3 7% 5% 4 4 3 5% 7% 33%	2601
	11th to 20th	Night	18% 13% 4 9% 6% 5% 4 3 5% 6% 27%	2800
	21st to end	Night	20% 17% 5% 8% 5% 4 5% 4 4 5% 23%	2800
December	1st to 10th	Night	16% 20% 5% 10% 5% 4 4 3 5% 5% 24%	2803
	11th to 20th	Night	17% 17% 4 10% 5% 4 4 3 4 5% 27%	3526
	21st to end	Night	25% 22% 6% 10% 5% 3 3 3 4 5% 16%	5236

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	66% 7% 12% 11% 4	2209
	11th to 20th	Day	66% 6% 13% 10% 4 1	2466
	21st to end	Day	72% 6% 8% 8% 6% 1	2935
February	1st to 10th	Day	60% 6% 12% 15% 6% 1	1710
	11th to 20th	Day	57% 5% 10% 15% 11% 2	1672
	21st to end	Day	61% 5% 9% 16% 9% 1	1532
March	1st to 10th	Day	52% 6% 15% 14% 12% 1	3270
	11th to 20th	Day	52% 5% 12% 21% 8% 2	3480
	21st to end	Day	52% 5% 12% 16% 11% 4	3815
April	1st to 10th	Day	55% 5% 12% 17% 11% 1	2242
	11th to 20th	Day	50% 5% 10% 22% 12% 2	2442
	21st to end	Day	49% 5% 10% 18% 14% 3	2470
May	1st to 10th	Day	44% 7% 11% 24% 12% 2	4120
	11th to 20th	Day	40% 6% 14% 24% 14% 1	4324
	21st to end	Day	40% 5% 13% 17% 19% 5%	5043
June	1st to 10th	Day	44% 6% 12% 22% 13% 2	2850
	11th to 20th	Day	42% 6% 12% 22% 17% 1	2850
	21st to end	Day	46% 7% 13% 20% 12% 2	2850
July	1st to 10th	Day	45% 7% 15% 21% 10% 1	4686
	11th to 20th	Day	34% 7% 16% 32% 10% 1	4679
	21st to end	Day	33% 6% 12% 32% 17%	4546
August	1st to 10th	Day	38% 8% 15% 28% 11% 1	4091
	11th to 20th	Day	40% 7% 17% 26% 11%	4083
	21st to end	Day	37% 7% 15% 30% 11% 1	4531
September	1st to 10th	Day	42% 8% 14% 25% 11% 1	2266
	11th to 20th	Day	37% 7% 16% 28% 12%	2090
	21st to end	Day	48% 7% 13% 23% 8% 1	2090
October	1st to 10th	Day	38% 5% 12% 29% 15%	3229
	11th to 20th	Day	46% 7% 14% 24% 8%	3140
	21st to end	Day	59% 6% 14% 14% 7% 1	3180
November	1st to 10th	Day	54% 5% 14% 20% 6%	1695
	11th to 20th	Day	60% 7% 12% 14% 7%	1600
	21st to end	Day	68% 4 10% 12% 5%	1600
December	1st to 10th	Day	62% 7% 12% 13% 5% 1	1489
	11th to 20th	Day	61% 7% 10% 15% 5% 1	1671
	21st to end	Day	72% 5% 7% 11% 5%	2431
January	1st to 10th	Night	61% 10% 12% 10% 7%	4748
	11th to 20th	Night	60% 8% 15% 13% 5%	4500
	21st to end	Night	67% 6% 9% 13% 5%	4724
February	1st to 10th	Night	59% 6% 10% 18% 7% 1	2470
	11th to 20th	Night	55% 5% 14% 17% 7% 1	2405
	21st to end	Night	57% 7% 12% 15% 9% 1	1918
March	1st to 10th	Night	48% 6% 12% 19% 13% 1	3583
	11th to 20th	Night	47% 6% 15% 20% 10% 2	3480
	21st to end	Night	48% 5% 12% 20% 13% 3	3817
April	1st to 10th	Night	51% 6% 9% 20% 13% 1	1953
	11th to 20th	Night	46% 5% 7% 24% 16% 1	1687
	21st to end	Night	51% 5% 10% 17% 15% 3	1710
May	1st to 10th	Night	45% 8% 10% 23% 11% 2	2840
	11th to 20th	Night	39% 7% 11% 26% 16% 1	2572
	21st to end	Night	39% 8% 11% 24% 12% 6%	2538
June	1st to 10th	Night	42% 7% 13% 22% 15% 2	1330
	11th to 20th	Night	38% 8% 12% 22% 19% 2	1330
	21st to end	Night	40% 6% 15% 24% 13% 2	1330
July	1st to 10th	Night	38% 6% 15% 24% 15% 2	2175
	11th to 20th	Night	33% 6% 14% 34% 12% 1	2168
	21st to end	Night	31% 6% 14% 29% 20%	2767
August	1st to 10th	Night	36% 9% 14% 27% 13% 1	2814
	11th to 20th	Night	36% 7% 19% 27% 10% 1	2812
	21st to end	Night	31% 7% 15% 33% 14% 1	3124
September	1st to 10th	Night	38% 6% 15% 28% 11% 2	1893
	11th to 20th	Night	31% 6% 17% 35% 11%	2090
	21st to end	Night	44% 7% 15% 25% 10%	2090
October	1st to 10th	Night	38% 6% 12% 28% 15%	3731
	11th to 20th	Night	43% 6% 14% 30% 7%	3779
	21st to end	Night	51% 7% 19% 17% 6%	4366
November	1st to 10th	Night	50% 6% 15% 21% 8%	2601
	11th to 20th	Night	58% 6% 13% 16% 8%	2800
	21st to end	Night	62% 8% 11% 12% 7%	2800
December	1st to 10th	Night	62% 7% 10% 16% 5%	2803
	11th to 20th	Night	58% 7% 12% 14% 8% 2	3525
	21st to end	Night	71% 5% 10% 9% 5%	5236

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	25% 19% 35% 15% 6%	180
	11th to 20th	Day	19% 18% 37% 20% 6% 1	252
	21st to end	Day	26% 13% 34% 21% 6% 1	297
February	1st to 10th	Day	23% 29% 31% 11% 5%	270
	11th to 20th	Day	21% 25% 40% 12% 2	270
	21st to end	Day	32% 28% 34% 7%	225
March	1st to 10th	Day	25% 22% 33% 16% 4	355
	11th to 20th	Day	23% 17% 36% 17% 6% 1	460
	21st to end	Day	27% 18% 32% 16% 4 1	506
April	1st to 10th	Day	24% 20% 28% 21% 6% 1	460
	11th to 20th	Day	31% 20% 23% 15% 8% 2	452
	21st to end	Day	32% 16% 28% 15% 7% 2	460
May	1st to 10th	Day	22% 16% 35% 18% 6% 3	463
	11th to 20th	Day	21% 17% 32% 19% 8% 3	487
	21st to end	Day	20% 14% 36% 21% 7% 2	644
June	1st to 10th	Day	16% 20% 38% 21% 5% 1	680
	11th to 20th	Day	19% 15% 37% 21% 6% 1	680
	21st to end	Day	20% 17% 34% 20% 7% 2	680
July	1st to 10th	Day	13% 16% 36% 27% 7% 2	671
	11th to 20th	Day	12% 13% 36% 26% 10% 3	668
	21st to end	Day	12% 11% 37% 26% 10% 4	665
August	1st to 10th	Day	16% 11% 25% 28% 15% 5%	486
	11th to 20th	Day	14% 7% 30% 26% 14% 9%	479
	21st to end	Day	16% 13% 29% 23% 14% 5%	539
September	1st to 10th	Day	18% 12% 28% 25% 12% 5%	490
	11th to 20th	Day	16% 10% 26% 30% 11% 7%	490
	21st to end	Day	28% 12% 22% 24% 11% 3	490
October	1st to 10th	Day	26% 14% 29% 19% 10% 2	490
	11th to 20th	Day	27% 19% 32% 17% 4 1	490
	21st to end	Day	34% 20% 30% 14% 1 1	392
November	1st to 10th	Day	29% 20% 34% 13% 5%	265
	11th to 20th	Day	26% 21% 32% 19% 3	200
	21st to end	Day	28% 24% 29% 16% 4 1	200
December	1st to 10th	Day	24% 14% 36% 18% 8%	190
	11th to 20th	Day	32% 18% 34% 14% 2	180
	21st to end	Day	36% 20% 28% 12% 3 1	198
January	1st to 10th	Night	23% 15% 33% 22% 6%	950
	11th to 20th	Night	26% 17% 27% 24% 6%	950
	21st to end	Night	22% 11% 33% 25% 9% 1	950
February	1st to 10th	Night	19% 18% 37% 22% 4	760
	11th to 20th	Night	18% 18% 34% 24% 5% 1	743
	21st to end	Night	22% 16% 36% 21% 4	628
March	1st to 10th	Night	17% 17% 38% 23% 4	760
	11th to 20th	Night	19% 16% 37% 21% 7%	760
	21st to end	Night	20% 14% 34% 25% 6% 1	836
April	1st to 10th	Night	24% 13% 34% 24% 5%	704
	11th to 20th	Night	25% 13% 29% 23% 9% 1	563
	21st to end	Night	24% 15% 26% 26% 9%	570
May	1st to 10th	Night	15% 10% 33% 32% 8% 1	570
	11th to 20th	Night	15% 10% 33% 31% 10%	424
	21st to end	Night	14% 11% 34% 30% 10%	411
June	1st to 10th	Night	15% 8% 38% 32% 7%	380
	11th to 20th	Night	14% 8% 34% 36% 8%	380
	21st to end	Night	15% 9% 28% 36% 12%	380
July	1st to 10th	Night	10% 7% 31% 42% 9%	370
	11th to 20th	Night	11% 4 29% 43% 14%	368
	21st to end	Night	11% 5% 29% 37% 16% 1	614
August	1st to 10th	Night	13% 4 25% 37% 19% 1	567
	11th to 20th	Night	13% 5% 22% 34% 23% 3	564
	21st to end	Night	14% 6% 27% 31% 21% 2	627
September	1st to 10th	Night	17% 7% 28% 30% 16% 2	711
	11th to 20th	Night	15% 9% 26% 28% 20% 3	760
	21st to end	Night	21% 9% 25% 28% 15% 2	760
October	1st to 10th	Night	24% 9% 29% 27% 11% 1	760
	11th to 20th	Night	29% 14% 28% 21% 8% 1	760
	21st to end	Night	30% 14% 29% 22% 4 1	836
November	1st to 10th	Night	26% 14% 28% 26% 6%	780
	11th to 20th	Night	27% 16% 27% 24% 7%	800
	21st to end	Night	31% 14% 31% 20% 5%	800
December	1st to 10th	Night	27% 16% 32% 19% 6%	849
	11th to 20th	Night	26% 17% 32% 19% 5% 1	950
	21st to end	Night	31% 17% 28% 19% 5%	1045

Page generated at 2024-12-03 06:45:10. Version ac07

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