Monte Cristo's Castle
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Monte Cristo's Castle clear sky chart from 2005-11-06 to 2026-03-18.

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	2 3 1 3 3 3 3 3 4 6% 70%	139543
	Night	2 3 1 4 3 3 3 3 4 7% 66%	139389
Transparency	Day	15% 4 6% 18% 27% 29%	134571
	Night	17% 5% 8% 21% 28% 22%	135338
Seeing	Day	4 8% 18% 29% 25% 15%	16790
	Night	3 4 18% 44% 28% 3	26433

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	1 4 3 7% 4 4 4 4 6% 8% 55%	4722
	11th to 20th	Day	1 3 1 4 3 3 4 3 4 5% 69%	4740
	21st to end	Day	2 6% 2 5% 3 4 4 4 6% 9% 55%	5736
February	1st to 10th	Day	2 5% 2 5% 3 3 3 3 5% 10% 59%	2100
	11th to 20th	Day	2 5% 2 5% 4 3 3 4 6% 10% 57%	2050
	21st to end	Day	1 4 2 5% 3 3 4 3 5% 8% 62%	1730
March	1st to 10th	Day	1 5% 2 6% 4 3 4 4 7% 10% 54%	4618
	11th to 20th	Day	2 4 2 5% 3 3 4 3 6% 8% 60%	4736
	21st to end	Day	2 5% 2 5% 4 4 4 4 6% 9% 56%	5962
April	1st to 10th	Day	2 4 1 4 4 3 4 3 5% 7% 63%	2400
	11th to 20th	Day	2 3 1 4 3 3 3 3 5% 7% 66%	2369
	21st to end	Day	2 4 2 4 3 3 3 3 5% 7% 65%	2425
May	1st to 10th	Day	3 3 1 3 3 2 3 2 4 5% 72%	5880
	11th to 20th	Day	2 2 1 3 3 2 2 2 4 4 74%	5841
	21st to end	Day	2 3 1 3 3 2 3 3 4 5% 72%	6658
June	1st to 10th	Day	2 3 2 4 3 3 3 3 5% 7% 65%	2800
	11th to 20th	Day	3 2 1 2 2 2 2 2 4 5% 76%	2800
	21st to end	Day	1 2 1 2 3 2 2 2 3 3 78%	2800
July	1st to 10th	Day	1 1 1 2 2 1 2 2 2 2 84%	6319
	11th to 20th	Day	2 2 1 2 2 2 3 2 4 5% 75%	6320
	21st to end	Day	2 2 1 2 2 3 3 3 4 5% 73%	6799
August	1st to 10th	Day	2 1 1 2 1 1 2 1 2 2 84%	5487
	11th to 20th	Day	1 1 1 1 1 1 1 2 3 87%	5364
	21st to end	Day	1 2 1 2 2 2 3 3 4 4 76%	5984
September	1st to 10th	Day	2 1 2 2 2 2 3 4 4 79%	2400
	11th to 20th	Day	2 2 1 2 2 2 2 1 4 3 80%	2255
	21st to end	Day	2 1 1 1 1 1 2 2 3 4 83%	2200
October	1st to 10th	Day	1 2 1 2 2 2 2 2 4 5% 78%	3600
	11th to 20th	Day	1 1 1 3 2 2 2 2 3 5% 78%	3301
	21st to end	Day	1 2 1 3 2 2 2 2 4 5% 77%	3297
November	1st to 10th	Day	1 2 1 3 2 2 3 3 4 8% 70%	1854
	11th to 20th	Day	2 3 1 3 2 3 3 3 4 8% 69%	1890
	21st to end	Day	1 3 1 3 3 3 3 3 5% 7% 66%	1890
December	1st to 10th	Day	1 2 1 3 2 2 3 3 4 6% 72%	3016
	11th to 20th	Day	2 6% 2 4 4 4 5% 4 7% 9% 54%	3108
	21st to end	Day	2 5% 2 6% 5% 5% 6% 5% 7% 9% 50%	4092
January	1st to 10th	Night	1 4 2 8% 4 3 3 3 5% 7% 59%	8172
	11th to 20th	Night	1 3 2 4 3 2 3 3 4 7% 68%	8220
	21st to end	Night	3 7% 2 5% 4 4 4 4 5% 8% 55%	8455
February	1st to 10th	Night	2 5% 2 5% 3 3 4 2 4 7% 63%	2520
	11th to 20th	Night	2 4 1 3 3 3 5% 3 7% 8% 61%	2458
	21st to end	Night	1 4 1 6% 3 3 3 3 6% 8% 62%	2076
March	1st to 10th	Night	2 5% 2 5% 3 3 4 4 5% 7% 61%	5496
	11th to 20th	Night	2 4 1 4 3 3 3 4 6% 8% 62%	5419
	21st to end	Night	2 5% 2 4 3 3 4 3 6% 7% 60%	5009
April	1st to 10th	Night	3 4 1 3 2 3 4 3 5% 6% 65%	2000
	11th to 20th	Night	2 4 1 4 3 2 3 3 5% 6% 68%	1979
	21st to end	Night	3 5% 1 3 3 2 3 3 5% 6% 65%	1972
May	1st to 10th	Night	5% 4 2 4 3 2 2 2 3 5% 68%	4100
	11th to 20th	Night	3 3 1 3 3 3 4 3 4 6% 68%	4074
	21st to end	Night	3 3 1 4 2 3 3 2 4 5% 68%	4209
June	1st to 10th	Night	3 2 1 4 3 3 4 4 5% 7% 65%	1600
	11th to 20th	Night	2 3 1 3 3 3 3 2 4 5% 72%	1600
	21st to end	Night	2 2 1 3 2 2 2 2 4 4 77%	1600
July	1st to 10th	Night	2 1 2 2 2 2 2 3 4 81%	3640
	11th to 20th	Night	3 3 2 4 4 3 4 4 4 6% 63%	3640
	21st to end	Night	3 2 1 3 3 3 3 3 4 5% 71%	4055
August	1st to 10th	Night	3 3 1 3 2 2 2 2 2 4 75%	4336
	11th to 20th	Night	2 2 1 2 2 2 2 2 3 4 79%	4506
	21st to end	Night	3 3 1 4 3 3 3 2 4 5% 70%	5015
September	1st to 10th	Night	2 2 1 3 2 2 3 2 3 5% 76%	2000
	11th to 20th	Night	2 2 1 4 2 2 3 2 4 5% 74%	2144
	21st to end	Night	2 2 2 2 1 2 2 3 4 80%	2200
October	1st to 10th	Night	3 2 1 2 2 2 2 2 3 4 76%	3600
	11th to 20th	Night	1 1 1 2 1 1 2 2 3 5% 81%	3855
	21st to end	Night	1 2 1 2 2 2 2 2 3 4 79%	4505
November	1st to 10th	Night	2 3 1 3 1 1 2 2 4 7% 75%	2665
	11th to 20th	Night	1 3 1 3 2 2 3 3 4 6% 70%	2730
	21st to end	Night	2 3 2 4 3 3 3 3 4 7% 67%	2730
December	1st to 10th	Night	1 2 1 3 2 3 3 3 5% 6% 70%	4387
	11th to 20th	Night	2 6% 1 4 3 3 4 4 7% 13% 52%	5316
	21st to end	Night	1 4 3 7% 5% 5% 6% 6% 8% 11% 43%	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	23% 6% 19% 31% 19% 2	4723
	11th to 20th	Day	16% 5% 9% 19% 33% 19%	4740
	21st to end	Day	23% 5% 11% 23% 28% 9%	5736
February	1st to 10th	Day	21% 4 12% 30% 24% 9%	2100
	11th to 20th	Day	22% 5% 8% 30% 28% 7%	2060
	21st to end	Day	19% 5% 12% 31% 24% 8%	1730
March	1st to 10th	Day	22% 6% 5% 27% 30% 11%	4618
	11th to 20th	Day	20% 5% 9% 34% 26% 7%	4736
	21st to end	Day	19% 9% 9% 25% 27% 10%	5962
April	1st to 10th	Day	19% 5% 7% 26% 27% 15%	2400
	11th to 20th	Day	17% 4 8% 20% 32% 18%	2372
	21st to end	Day	17% 5% 6% 27% 33% 12%	2425
May	1st to 10th	Day	14% 4 5% 21% 39% 18%	5880
	11th to 20th	Day	13% 4 3 16% 39% 25%	5844
	21st to end	Day	14% 4 3 13% 35% 31%	6659
June	1st to 10th	Day	18% 4 5% 16% 31% 26%	2800
	11th to 20th	Day	12% 3 3 9% 30% 43%	2800
	21st to end	Day	12% 2 2 6% 21% 58%	2800
July	1st to 10th	Day	8% 2 1 4 11% 75%	6251
	11th to 20th	Day	11% 3 1 5% 12% 67%	6245
	21st to end	Day	12% 3 2 11% 23% 49%	6601
August	1st to 10th	Day	12% 2 2 7% 23% 54%	3995
	11th to 20th	Day	6% 2 2 5% 12% 73%	3880
	21st to end	Day	7% 2 1 5% 23% 62%	4311
September	1st to 10th	Day	9% 4 3 8% 24% 53%	2400
	11th to 20th	Day	10% 2 3 12% 31% 42%	2255
	21st to end	Day	8% 2 3 13% 35% 41%	2200
October	1st to 10th	Day	10% 3 3 11% 34% 39%	3600
	11th to 20th	Day	10% 3 2 12% 44% 29%	3301
	21st to end	Day	11% 3 2 23% 46% 16%	3297
November	1st to 10th	Day	13% 4 8% 30% 32% 13%	1854
	11th to 20th	Day	14% 4 9% 31% 35% 7%	1890
	21st to end	Day	17% 4 9% 30% 31% 9%	1890
December	1st to 10th	Day	13% 4 8% 30% 34% 10%	3016
	11th to 20th	Day	23% 7% 13% 32% 21% 3	3108
	21st to end	Day	27% 7% 20% 27% 18% 1	4092
January	1st to 10th	Night	21% 6% 20% 30% 20% 3	8172
	11th to 20th	Night	15% 4 10% 21% 34% 15%	8220
	21st to end	Night	25% 6% 10% 24% 24% 10%	8455
February	1st to 10th	Night	22% 4 12% 28% 24% 11%	2520
	11th to 20th	Night	18% 5% 9% 30% 31% 7%	2459
	21st to end	Night	19% 6% 11% 33% 23% 8%	2076
March	1st to 10th	Night	20% 6% 5% 24% 31% 14%	5496
	11th to 20th	Night	17% 6% 8% 33% 29% 6%	5419
	21st to end	Night	18% 8% 12% 30% 26% 6%	5009
April	1st to 10th	Night	19% 4 10% 28% 27% 12%	2000
	11th to 20th	Night	17% 5% 6% 26% 30% 16%	1979
	21st to end	Night	19% 5% 7% 27% 32% 10%	1972
May	1st to 10th	Night	18% 4 6% 21% 37% 14%	4097
	11th to 20th	Night	16% 5% 5% 16% 40% 19%	4075
	21st to end	Night	15% 6% 4 12% 39% 23%	4209
June	1st to 10th	Night	17% 4 7% 17% 31% 24%	1600
	11th to 20th	Night	14% 4 3 11% 28% 41%	1600
	21st to end	Night	11% 3 3 6% 24% 53%	1600
July	1st to 10th	Night	9% 3 2 5% 8% 74%	3600
	11th to 20th	Night	19% 7% 2 5% 13% 54%	3592
	21st to end	Night	15% 4 3 10% 22% 46%	3941
August	1st to 10th	Night	19% 4 2 9% 23% 43%	3145
	11th to 20th	Night	9% 4 3 4 12% 68%	3256
	21st to end	Night	9% 4 2 7% 18% 61%	3608
September	1st to 10th	Night	12% 3 2 9% 22% 51%	2000
	11th to 20th	Night	13% 3 4 12% 27% 41%	2144
	21st to end	Night	9% 3 3 10% 33% 42%	2200
October	1st to 10th	Night	13% 3 3 10% 31% 39%	3600
	11th to 20th	Night	9% 2 2 14% 41% 32%	3855
	21st to end	Night	11% 3 2 17% 44% 23%	4505
November	1st to 10th	Night	11% 3 8% 29% 33% 16%	2665
	11th to 20th	Night	15% 4 8% 30% 32% 11%	2730
	21st to end	Night	18% 3 7% 28% 34% 10%	2730
December	1st to 10th	Night	15% 4 7% 27% 32% 15%	4387
	11th to 20th	Night	22% 5% 16% 29% 25% 3	5316
	21st to end	Night	29% 7% 18% 27% 17% 2	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	6% 6% 16% 43% 22% 7%	220
	11th to 20th	Day	2 6% 18% 33% 24% 17%	220
	21st to end	Day	4 8% 16% 26% 30% 15%	423
February	1st to 10th	Day	5% 10% 21% 33% 21% 10%	540
	11th to 20th	Day	5% 13% 22% 33% 19% 7%	535
	21st to end	Day	5% 12% 20% 38% 20% 5%	446
March	1st to 10th	Day	6% 15% 22% 31% 19% 6%	540
	11th to 20th	Day	7% 15% 24% 29% 19% 6%	529
	21st to end	Day	9% 17% 26% 30% 15% 4	550
April	1st to 10th	Day	8% 16% 21% 24% 20% 10%	500
	11th to 20th	Day	7% 17% 25% 25% 20% 5%	492
	21st to end	Day	6% 16% 24% 26% 17% 11%	500
May	1st to 10th	Day	6% 14% 26% 26% 18% 9%	503
	11th to 20th	Day	7% 14% 22% 26% 20% 12%	528
	21st to end	Day	6% 10% 18% 25% 25% 16%	573
June	1st to 10th	Day	5% 9% 16% 23% 26% 21%	530
	11th to 20th	Day	5% 11% 19% 28% 24% 13%	530
	21st to end	Day	3 6% 15% 28% 32% 17%	530
July	1st to 10th	Day	3 4 16% 29% 29% 19%	526
	11th to 20th	Day	2 3 12% 23% 33% 26%	524
	21st to end	Day	2 2 14% 27% 29% 25%	575
August	1st to 10th	Day	3 2 17% 32% 28% 17%	527
	11th to 20th	Day	1 3 17% 25% 28% 26%	517
	21st to end	Day	3 3 13% 24% 33% 23%	583
September	1st to 10th	Day	2 3 14% 28% 28% 25%	530
	11th to 20th	Day	4 5% 18% 29% 26% 18%	530
	21st to end	Day	3 5% 14% 25% 35% 17%	530
October	1st to 10th	Day	4 8% 18% 25% 25% 20%	530
	11th to 20th	Day	3 8% 15% 27% 30% 18%	530
	21st to end	Day	3 5% 14% 27% 30% 21%	423
November	1st to 10th	Day	1 3 12% 35% 28% 21%	330
	11th to 20th	Day	3 6% 13% 34% 25% 19%	330
	21st to end	Day	3 3 14% 32% 32% 15%	330
December	1st to 10th	Day	3 2 15% 35% 31% 14%	324
	11th to 20th	Day	3 5% 15% 30% 31% 15%	220
	21st to end	Day	5% 6% 19% 36% 28% 6%	242
January	1st to 10th	Night	4 2 20% 46% 24% 4	840
	11th to 20th	Night	2 2 19% 50% 24% 4	840
	21st to end	Night	4 2 18% 47% 26% 2	924
February	1st to 10th	Night	4 3 21% 45% 24% 3	840
	11th to 20th	Night	3 4 22% 48% 22% 2	824
	21st to end	Night	3 3 23% 52% 17% 1	692
March	1st to 10th	Night	4 5% 23% 47% 19% 1	840
	11th to 20th	Night	3 5% 21% 47% 22% 3	828
	21st to end	Night	4 8% 27% 41% 19% 1	880
April	1st to 10th	Night	4 8% 24% 43% 20% 1	800
	11th to 20th	Night	3 8% 24% 43% 19% 2	791
	21st to end	Night	5% 7% 24% 42% 20% 3	772
May	1st to 10th	Night	7% 11% 27% 37% 17% 1	600
	11th to 20th	Night	5% 8% 24% 39% 23% 1	591
	21st to end	Night	6% 8% 21% 40% 23% 2	541
June	1st to 10th	Night	3 5% 15% 44% 32% 3	400
	11th to 20th	Night	3 4 19% 49% 24% 1	400
	21st to end	Night	2 2 12% 57% 27%	400
July	1st to 10th	Night	2 8% 52% 37% 1	390
	11th to 20th	Night	4 1 7% 43% 45% 1	388
	21st to end	Night	5% 1 6% 43% 42% 2	473
August	1st to 10th	Night	6% 2 15% 42% 35% 1	723
	11th to 20th	Night	2 2 12% 40% 41% 4	792
	21st to end	Night	2 1 10% 40% 45% 3	880
September	1st to 10th	Night	3 2 9% 39% 44% 4	800
	11th to 20th	Night	2 2 14% 39% 38% 5%	800
	21st to end	Night	2 3 11% 39% 42% 4	800
October	1st to 10th	Night	3 2 16% 40% 35% 5%	800
	11th to 20th	Night	3 2 15% 41% 35% 4	800
	21st to end	Night	2 2 16% 38% 35% 8%	880
November	1st to 10th	Night	2 1 14% 42% 35% 5%	820
	11th to 20th	Night	2 2 14% 50% 29% 3	840
	21st to end	Night	3 1 17% 47% 28% 4	840
December	1st to 10th	Night	3 2 15% 54% 21% 5%	840
	11th to 20th	Night	5% 3 17% 50% 22% 3	840
	21st to end	Night	4 3 23% 51% 18% 2	924

Page generated at 2026-03-14 23:23:55. Version ac07

Copyright © 2026 Attilla Danko.