Manic-5
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Manic-5 clear sky chart from 2005-11-06 to 2026-09-29.

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	17% 12% 4 10% 6% 6% 5% 4 5% 6% 23%	150625
	Night	14% 13% 5% 11% 7% 6% 5% 4 6% 6% 22%	141022
Transparency	Day	60% 5% 11% 17% 7% 1	154004
	Night	60% 5% 11% 17% 6%	145734
Seeing	Day	27% 17% 29% 18% 7% 2	18417
	Night	24% 15% 31% 22% 8% 1	26104

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	10% 20% 8% 16% 8% 5% 4 3 5% 5% 16%	4093
	11th to 20th	Day	5% 17% 7% 16% 11% 9% 6% 4 6% 5% 14%	4194
	21st to end	Day	3 7% 3 12% 8% 9% 7% 8% 10% 8% 25%	5124
February	1st to 10th	Day	5% 11% 5% 10% 9% 8% 8% 5% 7% 8% 24%	1691
	11th to 20th	Day	7% 17% 7% 13% 8% 6% 6% 5% 7% 6% 19%	1843
	21st to end	Day	5% 15% 5% 13% 10% 6% 7% 6% 7% 6% 21%	1699
March	1st to 10th	Day	14% 13% 4 12% 7% 6% 5% 4 4 5% 26%	4576
	11th to 20th	Day	15% 21% 5% 12% 6% 6% 5% 4 4 4 17%	5043
	21st to end	Day	15% 17% 7% 11% 5% 5% 4 3 4 6% 24%	5674
April	1st to 10th	Day	16% 17% 6% 14% 6% 6% 4 3 3 3 22%	2579
	11th to 20th	Day	15% 15% 5% 10% 6% 5% 5% 4 5% 6% 27%	2702
	21st to end	Day	19% 15% 4 10% 6% 5% 3 3 4 5% 26%	2730
May	1st to 10th	Day	22% 16% 4 9% 5% 5% 4 3 5% 5% 21%	7990
	11th to 20th	Day	23% 11% 3 9% 5% 5% 5% 4 5% 6% 24%	8816
	21st to end	Day	22% 14% 4 9% 5% 4 4 3 4 5% 26%	9716
June	1st to 10th	Day	24% 10% 3 7% 5% 4 4 3 5% 5% 30%	3150
	11th to 20th	Day	21% 8% 3 9% 6% 5% 6% 4 5% 6% 26%	3150
	21st to end	Day	27% 9% 3 8% 6% 4 5% 4 5% 6% 24%	3150
July	1st to 10th	Day	14% 8% 3 8% 5% 6% 6% 5% 7% 7% 31%	8880
	11th to 20th	Day	18% 9% 3 10% 6% 6% 7% 5% 7% 6% 23%	8880
	21st to end	Day	16% 7% 3 9% 6% 7% 7% 5% 7% 9% 25%	9409
August	1st to 10th	Day	21% 7% 3 8% 6% 6% 6% 4 6% 8% 25%	6447
	11th to 20th	Day	17% 10% 4 10% 6% 6% 6% 6% 7% 7% 20%	5953
	21st to end	Day	18% 8% 3 8% 6% 6% 6% 5% 6% 7% 27%	6594
September	1st to 10th	Day	21% 9% 3 9% 6% 5% 5% 4 5% 6% 29%	2582
	11th to 20th	Day	27% 8% 3 8% 5% 4 4 3 4 6% 27%	2310
	21st to end	Day	21% 11% 4 8% 6% 5% 5% 3 4 5% 28%	2288
October	1st to 10th	Day	22% 13% 3 9% 5% 6% 4 3 5% 5% 24%	2091
	11th to 20th	Day	27% 18% 5% 10% 5% 4 4 3 4 5% 16%	1870
	21st to end	Day	26% 21% 5% 10% 4 4 4 2 3 4 17%	1980
November	1st to 10th	Day	18% 21% 8% 14% 7% 6% 4 4 4 3 11%	1723
	11th to 20th	Day	19% 20% 5% 15% 9% 5% 4 3 3 3 14%	1637
	21st to end	Day	15% 24% 8% 14% 7% 5% 4 3 3 4 14%	1470
December	1st to 10th	Day	10% 16% 7% 18% 12% 7% 5% 3 4 5% 13%	2350
	11th to 20th	Day	14% 14% 6% 15% 9% 7% 7% 4 5% 5% 14%	2688
	21st to end	Day	11% 15% 6% 12% 7% 6% 7% 4 5% 7% 20%	3553
January	1st to 10th	Night	9% 22% 8% 18% 7% 6% 5% 3 4 4 12%	8831
	11th to 20th	Night	6% 18% 7% 17% 10% 8% 6% 4 6% 6% 13%	8711
	21st to end	Night	3 6% 3 11% 8% 9% 8% 8% 11% 9% 23%	9057
February	1st to 10th	Night	5% 11% 4 12% 9% 8% 8% 5% 9% 7% 22%	2928
	11th to 20th	Night	7% 16% 6% 14% 8% 5% 7% 5% 7% 7% 17%	2663
	21st to end	Night	6% 14% 6% 11% 8% 6% 8% 6% 7% 7% 22%	2104
March	1st to 10th	Night	12% 14% 5% 11% 6% 6% 5% 4 5% 7% 25%	5484
	11th to 20th	Night	15% 19% 6% 14% 7% 6% 6% 4 4 4 16%	5122
	21st to end	Night	13% 19% 6% 11% 6% 6% 6% 4 5% 5% 21%	5496
April	1st to 10th	Night	16% 16% 5% 11% 5% 5% 5% 4 5% 5% 23%	2040
	11th to 20th	Night	16% 12% 4 9% 6% 4 4 3 4 5% 32%	1868
	21st to end	Night	19% 13% 4 9% 7% 5% 5% 4 5% 4 26%	1890
May	1st to 10th	Night	20% 15% 4 9% 5% 4 4 3 4 5% 26%	4958
	11th to 20th	Night	23% 9% 4 9% 6% 5% 4 3 4 6% 27%	4074
	21st to end	Night	20% 15% 5% 9% 5% 4 4 3 5% 5% 26%	4491
June	1st to 10th	Night	20% 10% 2 7% 6% 5% 4 3 7% 7% 29%	1470
	11th to 20th	Night	22% 9% 3 8% 6% 5% 5% 5% 6% 6% 26%	1470
	21st to end	Night	23% 9% 3 6% 4 4 5% 4 7% 8% 26%	1470
July	1st to 10th	Night	14% 6% 2 6% 4 5% 6% 5% 8% 10% 33%	4110
	11th to 20th	Night	15% 8% 3 9% 6% 5% 6% 5% 7% 9% 27%	4110
	21st to end	Night	13% 6% 3 7% 5% 6% 7% 5% 7% 9% 32%	4685
August	1st to 10th	Night	19% 8% 3 7% 4 4 4 3 6% 8% 33%	3666
	11th to 20th	Night	16% 8% 3 9% 6% 7% 7% 5% 6% 7% 26%	4069
	21st to end	Night	14% 6% 3 8% 4 5% 5% 4 6% 7% 39%	4531
September	1st to 10th	Night	21% 8% 3 7% 4 4 4 4 6% 7% 32%	2035
	11th to 20th	Night	22% 8% 3 8% 4 4 4 3 5% 6% 32%	2310
	21st to end	Night	19% 9% 3 6% 5% 4 5% 3 5% 6% 34%	2289
October	1st to 10th	Night	21% 11% 3 9% 5% 5% 4 3 5% 5% 30%	2308
	11th to 20th	Night	25% 15% 4 11% 6% 4 3 3 4 5% 21%	2527
	21st to end	Night	26% 15% 5% 10% 5% 4 4 3 4 5% 18%	2860
November	1st to 10th	Night	21% 16% 5% 12% 7% 5% 5% 4 5% 5% 15%	2795
	11th to 20th	Night	17% 19% 6% 14% 7% 5% 5% 3 4 5% 14%	2982
	21st to end	Night	18% 20% 7% 15% 9% 6% 4 3 4 3 10%	3150
December	1st to 10th	Night	10% 16% 7% 18% 10% 6% 6% 3 4 4 16%	5060
	11th to 20th	Night	16% 14% 6% 15% 8% 6% 5% 4 4 5% 17%	5741
	21st to end	Night	11% 16% 5% 11% 6% 6% 5% 5% 6% 9% 18%	7667

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	70% 4 7% 16% 3	4094
	11th to 20th	Day	69% 3 10% 12% 5%	4220
	21st to end	Day	48% 7% 10% 21% 13% 1	5124
February	1st to 10th	Day	55% 5% 9% 18% 12% 1	1691
	11th to 20th	Day	63% 4 9% 14% 9%	1851
	21st to end	Day	59% 4 8% 19% 9% 1	1699
March	1st to 10th	Day	61% 3 7% 17% 11% 1	4579
	11th to 20th	Day	70% 5% 5% 11% 8% 1	5043
	21st to end	Day	61% 4 7% 15% 12% 2	5674
April	1st to 10th	Day	68% 4 6% 13% 10%	2579
	11th to 20th	Day	59% 4 8% 16% 12% 1	2702
	21st to end	Day	61% 4 10% 15% 10% 1	2730
May	1st to 10th	Day	63% 6% 8% 15% 7% 1	8002
	11th to 20th	Day	58% 5% 10% 18% 7% 1	8820
	21st to end	Day	60% 4 8% 18% 10% 1	9717
June	1st to 10th	Day	55% 6% 8% 19% 10% 2	3150
	11th to 20th	Day	57% 7% 10% 15% 11% 1	3150
	21st to end	Day	61% 6% 9% 15% 8% 1	3150
July	1st to 10th	Day	48% 6% 10% 25% 10%	8805
	11th to 20th	Day	57% 7% 13% 16% 7%	8799
	21st to end	Day	52% 7% 15% 20% 5% 1	9201
August	1st to 10th	Day	54% 7% 16% 19% 4	6433
	11th to 20th	Day	59% 7% 16% 15% 3	5992
	21st to end	Day	53% 7% 16% 18% 6% 1	6594
September	1st to 10th	Day	55% 7% 14% 18% 6%	2582
	11th to 20th	Day	57% 5% 15% 19% 4	2310
	21st to end	Day	57% 5% 11% 20% 7%	2288
October	1st to 10th	Day	61% 4 11% 19% 5%	3403
	11th to 20th	Day	71% 4 10% 14% 2	3021
	21st to end	Day	64% 4 12% 15% 4 1	3180
November	1st to 10th	Day	75% 6% 9% 9% 1	1723
	11th to 20th	Day	75% 4 10% 9% 1	1637
	21st to end	Day	75% 4 11% 8% 2	1470
December	1st to 10th	Day	73% 5% 10% 6% 5%	2350
	11th to 20th	Day	68% 5% 12% 11% 4	2688
	21st to end	Day	61% 5% 7% 20% 5% 1	3553
January	1st to 10th	Night	74% 3 7% 13% 3	8831
	11th to 20th	Night	69% 4 10% 12% 5%	8760
	21st to end	Night	48% 7% 12% 22% 9% 1	9057
February	1st to 10th	Night	56% 4 10% 17% 11% 1	2928
	11th to 20th	Night	62% 4 9% 17% 7%	2666
	21st to end	Night	59% 4 10% 17% 9% 1	2104
March	1st to 10th	Night	57% 4 7% 16% 15%	5494
	11th to 20th	Night	72% 4 6% 11% 6% 1	5123
	21st to end	Night	64% 5% 5% 13% 12% 1	5496
April	1st to 10th	Night	62% 5% 8% 13% 12% 1	2040
	11th to 20th	Night	53% 5% 10% 16% 14% 1	1868
	21st to end	Night	60% 4 9% 15% 11%	1890
May	1st to 10th	Night	59% 5% 8% 17% 10%	4964
	11th to 20th	Night	58% 5% 10% 20% 7%	4075
	21st to end	Night	60% 4 7% 21% 7%	4492
June	1st to 10th	Night	52% 6% 10% 20% 10% 1	1470
	11th to 20th	Night	56% 7% 11% 14% 11% 1	1470
	21st to end	Night	54% 7% 10% 16% 11%	1470
July	1st to 10th	Night	43% 6% 17% 25% 9% 1	4075
	11th to 20th	Night	50% 6% 19% 20% 5%	4068
	21st to end	Night	45% 7% 20% 23% 5%	4579
August	1st to 10th	Night	48% 7% 21% 21% 3	3656
	11th to 20th	Night	55% 6% 21% 16% 2	4096
	21st to end	Night	42% 6% 18% 28% 5%	4531
September	1st to 10th	Night	50% 7% 16% 22% 5%	2035
	11th to 20th	Night	53% 5% 16% 20% 5%	2310
	21st to end	Night	49% 6% 13% 24% 7%	2289
October	1st to 10th	Night	57% 4 12% 22% 4 1	3776
	11th to 20th	Night	65% 4 14% 13% 3	4115
	21st to end	Night	67% 6% 10% 15% 2 1	4610
November	1st to 10th	Night	69% 5% 12% 10% 2	2795
	11th to 20th	Night	71% 5% 13% 9% 2	2982
	21st to end	Night	78% 4 10% 7% 2	3150
December	1st to 10th	Night	69% 6% 11% 11% 2	5060
	11th to 20th	Night	68% 4 12% 13% 4	5742
	21st to end	Night	61% 7% 8% 17% 5% 1	7667

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% 18% 35% 23% 8% 1	220
	11th to 20th	Day	20% 15% 36% 17% 9% 3	220
	21st to end	Day	14% 20% 31% 25% 8% 2	242
February	1st to 10th	Day	13% 19% 40% 16% 8% 5%	231
	11th to 20th	Day	15% 23% 35% 21% 6% 1	426
	21st to end	Day	20% 17% 39% 17% 6% 1	430
March	1st to 10th	Day	20% 22% 31% 20% 6% 1	540
	11th to 20th	Day	21% 19% 35% 18% 6% 1	540
	21st to end	Day	25% 22% 31% 15% 6% 1	594
April	1st to 10th	Day	29% 20% 34% 13% 4 1	540
	11th to 20th	Day	27% 20% 29% 16% 5% 3	532
	21st to end	Day	30% 20% 28% 14% 6% 2	540
May	1st to 10th	Day	34% 16% 23% 18% 7% 1	580
	11th to 20th	Day	27% 17% 26% 19% 9% 2	774
	21st to end	Day	33% 19% 24% 18% 6% 1	845
June	1st to 10th	Day	29% 15% 25% 23% 7% 1	780
	11th to 20th	Day	27% 16% 28% 18% 9% 2	780
	21st to end	Day	30% 16% 24% 20% 7% 2	780
July	1st to 10th	Day	23% 14% 28% 23% 10% 1	770
	11th to 20th	Day	26% 13% 29% 22% 8% 2	768
	21st to end	Day	23% 12% 30% 24% 9% 2	766
August	1st to 10th	Day	27% 11% 31% 18% 10% 3	566
	11th to 20th	Day	24% 12% 28% 24% 10% 2	559
	21st to end	Day	26% 13% 28% 18% 10% 5%	627
September	1st to 10th	Day	27% 18% 30% 15% 6% 3	570
	11th to 20th	Day	33% 17% 26% 13% 8% 2	570
	21st to end	Day	26% 19% 27% 18% 7% 3	562
October	1st to 10th	Day	28% 20% 29% 14% 6% 2	469
	11th to 20th	Day	41% 13% 23% 13% 6% 4	420
	21st to end	Day	35% 18% 24% 15% 8% 1	462
November	1st to 10th	Day	34% 25% 27% 10% 3 1	425
	11th to 20th	Day	32% 14% 31% 15% 6% 2	387
	21st to end	Day	26% 24% 35% 9% 6%	220
December	1st to 10th	Day	15% 17% 31% 22% 10% 4	220
	11th to 20th	Day	25% 23% 31% 16% 4	220
	21st to end	Day	22% 19% 32% 15% 11% 1	242
January	1st to 10th	Night	17% 16% 34% 25% 7%	950
	11th to 20th	Night	21% 16% 31% 23% 9%	928
	21st to end	Night	12% 14% 37% 28% 8% 1	924
February	1st to 10th	Night	11% 15% 41% 22% 10% 1	840
	11th to 20th	Night	18% 16% 35% 23% 8%	823
	21st to end	Night	15% 15% 35% 24% 9% 2	692
March	1st to 10th	Night	16% 18% 36% 24% 6%	840
	11th to 20th	Night	21% 18% 31% 23% 7% 1	840
	21st to end	Night	21% 19% 32% 22% 6%	924
April	1st to 10th	Night	26% 16% 34% 18% 5%	780
	11th to 20th	Night	23% 17% 32% 18% 8% 1	624
	21st to end	Night	29% 13% 28% 21% 8%	630
May	1st to 10th	Night	30% 11% 29% 23% 7% 1	565
	11th to 20th	Night	26% 12% 31% 22% 8% 1	414
	21st to end	Night	25% 14% 36% 22% 4	455
June	1st to 10th	Night	24% 13% 30% 26% 7%	420
	11th to 20th	Night	25% 11% 32% 24% 8%	420
	21st to end	Night	27% 10% 27% 26% 9% 1	420
July	1st to 10th	Night	19% 8% 32% 32% 8%	410
	11th to 20th	Night	20% 10% 28% 29% 13%	408
	21st to end	Night	21% 9% 26% 30% 12% 1	460
August	1st to 10th	Night	23% 7% 25% 29% 16% 1	418
	11th to 20th	Night	26% 9% 26% 28% 11%	612
	21st to end	Night	25% 10% 26% 27% 11% 2	693
September	1st to 10th	Night	26% 13% 30% 23% 7%	728
	11th to 20th	Night	29% 16% 25% 22% 8%	840
	21st to end	Night	26% 15% 27% 23% 8% 1	833
October	1st to 10th	Night	29% 17% 29% 18% 6% 1	800
	11th to 20th	Night	32% 13% 25% 21% 8% 1	800
	21st to end	Night	36% 13% 25% 18% 7%	880
November	1st to 10th	Night	32% 19% 30% 15% 5%	888
	11th to 20th	Night	28% 17% 29% 17% 8% 1	950
	21st to end	Night	29% 16% 31% 19% 5%	950
December	1st to 10th	Night	24% 15% 30% 22% 8% 2	950
	11th to 20th	Night	23% 16% 34% 21% 6% 1	950
	21st to end	Night	22% 16% 31% 22% 8% 2	1045

Page generated at 2026-09-26 04:18:40. Version ac07

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