Kaladar
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Kaladar clear sky chart from 2005-11-06 to 2024-02-05.

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% 10% 4 7% 6% 3 5% 5% 5% 7% 32%	78124
	Night	17% 10% 4 7% 6% 3 5% 4 5% 6% 32%	80731
Transparency	Day	51% 7% 12% 18% 10% 1	77829
	Night	51% 8% 12% 18% 10% 1	80560
Seeing	Day	22% 17% 31% 19% 8% 3	13404
	Night	22% 14% 31% 24% 9% 1	22765

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	15% 16% 6% 10% 7% 3 4 4 4 5% 26%	2517
	11th to 20th	Day	14% 16% 7% 12% 7% 3 6% 5% 4 5% 21%	2520
	21st to end	Day	19% 19% 8% 12% 7% 4 4 3 3 3 19%	3060
February	1st to 10th	Day	14% 16% 4 11% 7% 4 6% 5% 5% 6% 21%	1656
	11th to 20th	Day	14% 14% 5% 11% 7% 3 5% 4 3 5% 28%	1573
	21st to end	Day	19% 14% 5% 9% 7% 4 4 5% 4 5% 24%	1439
March	1st to 10th	Day	16% 11% 4 9% 8% 4 5% 4 5% 5% 29%	1873
	11th to 20th	Day	13% 15% 5% 8% 7% 4 5% 4 5% 4 31%	1980
	21st to end	Day	20% 12% 4 5% 4 2 3 3 4 5% 38%	2240
April	1st to 10th	Day	20% 13% 5% 8% 5% 3 4 3 3 5% 32%	2160
	11th to 20th	Day	20% 8% 3 5% 4 3 4 3 4 7% 38%	2134
	21st to end	Day	21% 9% 4 7% 7% 3 4 4 4 5% 32%	2292
May	1st to 10th	Day	19% 8% 3 6% 6% 3 4 5% 6% 6% 33%	2484
	11th to 20th	Day	16% 7% 3 7% 5% 3 5% 4 5% 7% 39%	2478
	21st to end	Day	13% 6% 3 6% 5% 4 5% 6% 6% 8% 39%	2725
June	1st to 10th	Day	20% 7% 3 6% 6% 3 6% 5% 6% 7% 30%	2520
	11th to 20th	Day	16% 5% 2 5% 6% 3 6% 5% 6% 9% 37%	2520
	21st to end	Day	17% 7% 2 6% 6% 4 5% 5% 6% 8% 34%	2520
July	1st to 10th	Day	12% 5% 2 5% 6% 4 6% 6% 6% 9% 40%	2520
	11th to 20th	Day	12% 5% 3 6% 6% 3 6% 6% 7% 11% 36%	2520
	21st to end	Day	11% 6% 3 6% 6% 5% 7% 6% 7% 10% 35%	2744
August	1st to 10th	Day	11% 6% 3 6% 7% 4 7% 5% 6% 9% 38%	2359
	11th to 20th	Day	13% 6% 3 6% 6% 4 6% 6% 7% 9% 36%	2303
	21st to end	Day	14% 7% 2 7% 5% 3 4 6% 6% 9% 38%	2394
September	1st to 10th	Day	13% 6% 3 6% 5% 3 5% 5% 6% 7% 42%	2160
	11th to 20th	Day	12% 5% 3 5% 4 3 4 5% 4 8% 47%	2160
	21st to end	Day	18% 6% 2 5% 5% 3 4 4 6% 8% 37%	1894
October	1st to 10th	Day	20% 9% 3 6% 5% 3 4 5% 5% 6% 35%	1800
	11th to 20th	Day	22% 9% 3 7% 6% 4 5% 5% 6% 7% 27%	1800
	21st to end	Day	26% 11% 3 6% 6% 3 5% 4 4 5% 25%	1910
November	1st to 10th	Day	16% 8% 4 8% 6% 3 5% 5% 5% 7% 35%	1631
	11th to 20th	Day	18% 11% 5% 8% 6% 3 5% 4 5% 6% 29%	1520
	21st to end	Day	23% 13% 4 7% 6% 3 5% 5% 5% 6% 23%	1520
December	1st to 10th	Day	21% 16% 5% 9% 6% 4 5% 5% 5% 6% 19%	1520
	11th to 20th	Day	19% 15% 6% 8% 5% 3 4 4 4 5% 26%	1906
	21st to end	Day	27% 18% 4 10% 6% 3 3 3 3 3 20%	2772
January	1st to 10th	Night	19% 14% 7% 11% 7% 4 5% 4 5% 5% 20%	4429
	11th to 20th	Night	14% 13% 5% 10% 10% 5% 6% 5% 6% 5% 20%	4440
	21st to end	Night	19% 16% 7% 11% 7% 3 4 4 4 5% 20%	4592
February	1st to 10th	Night	14% 15% 5% 10% 7% 3 5% 5% 6% 6% 24%	2399
	11th to 20th	Night	14% 13% 6% 7% 7% 4 5% 4 5% 6% 29%	2273
	21st to end	Night	16% 13% 5% 7% 6% 3 5% 4 5% 6% 30%	1816
March	1st to 10th	Night	15% 11% 5% 7% 6% 3 5% 4 5% 6% 34%	2074
	11th to 20th	Night	17% 13% 4 7% 5% 2 3 4 5% 6% 34%	1979
	21st to end	Night	17% 8% 4 7% 5% 3 4 3 4 6% 39%	2116
April	1st to 10th	Night	20% 10% 4 7% 4 2 4 4 5% 6% 35%	1800
	11th to 20th	Night	18% 7% 2 7% 5% 3 4 4 5% 5% 39%	1775
	21st to end	Night	19% 9% 3 6% 5% 4 5% 4 5% 7% 34%	1684
May	1st to 10th	Night	21% 7% 2 5% 4 4 3 5% 5% 7% 37%	1474
	11th to 20th	Night	13% 6% 3 5% 5% 2 5% 4 6% 7% 44%	1415
	21st to end	Night	11% 5% 3 4 4 4 5% 4 5% 7% 48%	1550
June	1st to 10th	Night	15% 6% 3 5% 7% 3 6% 5% 6% 8% 35%	1440
	11th to 20th	Night	12% 7% 3 5% 5% 3 4 4 5% 10% 43%	1440
	21st to end	Night	14% 5% 3 5% 7% 3 5% 5% 5% 9% 40%	1440
July	1st to 10th	Night	8% 5% 3 6% 6% 3 4 5% 5% 8% 48%	1440
	11th to 20th	Night	12% 4 2 5% 5% 3 5% 4 6% 9% 45%	1440
	21st to end	Night	10% 5% 2 4 5% 3 4 5% 6% 8% 48%	1574
August	1st to 10th	Night	9% 6% 2 4 6% 3 5% 5% 5% 8% 47%	1575
	11th to 20th	Night	8% 6% 3 5% 7% 4 4 5% 6% 8% 45%	1598
	21st to end	Night	11% 6% 2 5% 5% 2 4 5% 5% 9% 46%	1944
September	1st to 10th	Night	11% 6% 2 5% 4 3 4 4 6% 8% 46%	1800
	11th to 20th	Night	13% 4 2 4 5% 2 3 4 6% 7% 51%	1800
	21st to end	Night	16% 5% 3 6% 5% 2 5% 4 5% 6% 44%	2063
October	1st to 10th	Night	17% 7% 3 7% 4 3 4 5% 5% 6% 39%	2160
	11th to 20th	Night	22% 8% 4 7% 6% 3 4 5% 5% 6% 30%	2160
	21st to end	Night	22% 10% 4 7% 6% 3 4 5% 4 7% 28%	2444
November	1st to 10th	Night	18% 8% 3 5% 5% 3 4 4 5% 6% 37%	2445
	11th to 20th	Night	19% 10% 3 6% 6% 3 5% 5% 4 6% 32%	2660
	21st to end	Night	21% 12% 5% 7% 5% 4 5% 4 6% 5% 26%	2660
December	1st to 10th	Night	21% 15% 5% 8% 6% 3 5% 6% 5% 6% 20%	2660
	11th to 20th	Night	20% 16% 5% 8% 6% 3 4 3 4 5% 28%	3288
	21st to end	Night	29% 17% 4 8% 6% 3 4 4 4 5% 16%	4884

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	56% 11% 14% 11% 6% 2	2518
	11th to 20th	Day	64% 8% 12% 10% 7%	2520
	21st to end	Day	71% 5% 8% 9% 5% 1	3060
February	1st to 10th	Day	63% 7% 11% 14% 5% 1	1656
	11th to 20th	Day	59% 6% 10% 15% 10% 1	1582
	21st to end	Day	64% 5% 8% 12% 10% 1	1439
March	1st to 10th	Day	57% 5% 13% 14% 9% 2	1876
	11th to 20th	Day	55% 7% 10% 16% 11% 2	1980
	21st to end	Day	50% 4 8% 19% 13% 6%	2240
April	1st to 10th	Day	56% 4 7% 18% 12% 3	2160
	11th to 20th	Day	46% 6% 9% 22% 16% 2	2134
	21st to end	Day	54% 5% 8% 15% 14% 4	2292
May	1st to 10th	Day	49% 6% 11% 16% 14% 4	2484
	11th to 20th	Day	45% 6% 11% 20% 15% 3	2482
	21st to end	Day	41% 9% 14% 19% 14% 2	2725
June	1st to 10th	Day	50% 9% 11% 17% 13% 1	2520
	11th to 20th	Day	42% 8% 12% 23% 13% 2	2520
	21st to end	Day	47% 8% 15% 17% 12% 1	2520
July	1st to 10th	Day	37% 9% 12% 25% 15% 1	2450
	11th to 20th	Day	38% 10% 17% 25% 10%	2445
	21st to end	Day	42% 9% 16% 22% 10% 1	2591
August	1st to 10th	Day	40% 10% 15% 23% 11% 1	2345
	11th to 20th	Day	42% 9% 16% 23% 10% 1	2303
	21st to end	Day	41% 8% 14% 25% 11% 1	2394
September	1st to 10th	Day	39% 9% 14% 26% 13% 1	2160
	11th to 20th	Day	35% 7% 13% 29% 15% 1	2160
	21st to end	Day	43% 8% 13% 27% 8%	1894
October	1st to 10th	Day	49% 7% 12% 20% 11% 1	1800
	11th to 20th	Day	54% 8% 15% 16% 6% 1	1800
	21st to end	Day	60% 7% 10% 16% 7%	1910
November	1st to 10th	Day	46% 10% 15% 19% 9% 1	1631
	11th to 20th	Day	56% 6% 12% 16% 9% 1	1520
	21st to end	Day	60% 9% 12% 10% 8%	1520
December	1st to 10th	Day	65% 9% 11% 10% 4	1520
	11th to 20th	Day	60% 8% 14% 11% 6%	1906
	21st to end	Day	70% 5% 7% 13% 5%	2772
January	1st to 10th	Night	61% 10% 13% 12% 4	4429
	11th to 20th	Night	61% 10% 14% 9% 4 1	4440
	21st to end	Night	65% 8% 11% 10% 6% 1	4592
February	1st to 10th	Night	59% 7% 12% 16% 6%	2399
	11th to 20th	Night	56% 6% 10% 20% 8% 1	2275
	21st to end	Night	54% 6% 12% 18% 10% 1	1816
March	1st to 10th	Night	51% 6% 12% 18% 12% 1	2084
	11th to 20th	Night	51% 5% 12% 20% 11% 1	1980
	21st to end	Night	47% 5% 9% 20% 16% 3	2116
April	1st to 10th	Night	50% 4 9% 21% 14% 3	1800
	11th to 20th	Night	46% 6% 10% 19% 17% 1	1775
	21st to end	Night	49% 7% 9% 16% 15% 3	1684
May	1st to 10th	Night	46% 6% 9% 18% 16% 5%	1474
	11th to 20th	Night	38% 6% 11% 26% 16% 3	1416
	21st to end	Night	35% 8% 15% 20% 19% 3	1551
June	1st to 10th	Night	45% 8% 13% 20% 12% 1	1440
	11th to 20th	Night	36% 8% 14% 20% 19% 2	1440
	21st to end	Night	41% 9% 16% 21% 12% 1	1440
July	1st to 10th	Night	32% 8% 13% 25% 20% 3	1400
	11th to 20th	Night	35% 8% 14% 30% 13%	1392
	21st to end	Night	31% 9% 17% 30% 13% 1	1486
August	1st to 10th	Night	34% 9% 18% 28% 11% 1	1565
	11th to 20th	Night	35% 9% 15% 27% 12% 1	1598
	21st to end	Night	34% 9% 15% 29% 13%	1944
September	1st to 10th	Night	35% 9% 15% 27% 14% 1	1800
	11th to 20th	Night	31% 9% 15% 31% 13% 1	1800
	21st to end	Night	40% 8% 12% 29% 10% 1	2063
October	1st to 10th	Night	45% 9% 11% 20% 14% 1	2160
	11th to 20th	Night	52% 8% 14% 18% 8%	2160
	21st to end	Night	56% 7% 14% 14% 10%	2444
November	1st to 10th	Night	46% 6% 15% 21% 10% 1	2445
	11th to 20th	Night	51% 7% 13% 18% 10% 2	2660
	21st to end	Night	57% 9% 13% 16% 5%	2660
December	1st to 10th	Night	64% 8% 12% 12% 4	2660
	11th to 20th	Night	60% 6% 12% 15% 7% 1	3288
	21st to end	Night	69% 8% 9% 11% 3	4884

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% 24% 29% 17% 4	180
	11th to 20th	Day	29% 22% 32% 13% 4 1	180
	21st to end	Day	27% 21% 34% 15% 3	279
February	1st to 10th	Day	31% 31% 28% 9% 1	252
	11th to 20th	Day	30% 26% 39% 4	240
	21st to end	Day	37% 20% 32% 9% 1	305
March	1st to 10th	Day	25% 23% 35% 14% 4	420
	11th to 20th	Day	26% 22% 33% 14% 5%	420
	21st to end	Day	34% 19% 27% 14% 5% 1	462
April	1st to 10th	Day	28% 23% 30% 14% 5%	420
	11th to 20th	Day	30% 23% 21% 17% 8% 2	412
	21st to end	Day	27% 21% 33% 11% 6% 2	420
May	1st to 10th	Day	24% 19% 29% 18% 6% 4	423
	11th to 20th	Day	17% 17% 37% 19% 7% 3	447
	21st to end	Day	16% 17% 34% 20% 9% 4	485
June	1st to 10th	Day	24% 12% 37% 20% 6% 2	450
	11th to 20th	Day	15% 19% 30% 23% 12% 2	450
	21st to end	Day	20% 13% 33% 22% 10% 3	450
July	1st to 10th	Day	12% 10% 29% 31% 16% 2	445
	11th to 20th	Day	14% 10% 31% 27% 14% 3	444
	21st to end	Day	13% 9% 37% 27% 10% 3	488
August	1st to 10th	Day	11% 8% 30% 31% 14% 5%	446
	11th to 20th	Day	12% 7% 28% 31% 17% 5%	439
	21st to end	Day	14% 11% 33% 23% 12% 7%	495
September	1st to 10th	Day	14% 13% 30% 23% 13% 7%	450
	11th to 20th	Day	12% 11% 27% 23% 16% 11%	450
	21st to end	Day	19% 12% 29% 23% 12% 6%	450
October	1st to 10th	Day	26% 18% 24% 16% 12% 4	450
	11th to 20th	Day	26% 23% 28% 17% 5% 1	450
	21st to end	Day	31% 20% 27% 19% 3	459
November	1st to 10th	Day	29% 16% 27% 21% 7%	325
	11th to 20th	Day	29% 21% 34% 10% 4 1	180
	21st to end	Day	28% 20% 36% 12% 3 1	180
December	1st to 10th	Day	31% 21% 34% 11% 3 1	180
	11th to 20th	Day	36% 25% 28% 9% 2 1	180
	21st to end	Day	33% 23% 32% 9% 2 1	198
January	1st to 10th	Night	27% 17% 32% 19% 4	760
	11th to 20th	Night	27% 17% 32% 19% 5% 1	760
	21st to end	Night	21% 16% 35% 25% 4 1	836
February	1st to 10th	Night	23% 20% 37% 17% 2	739
	11th to 20th	Night	22% 18% 39% 17% 4	703
	21st to end	Night	25% 18% 36% 17% 3	592
March	1st to 10th	Night	22% 18% 36% 21% 3	720
	11th to 20th	Night	25% 19% 30% 21% 3 1	720
	21st to end	Night	22% 15% 35% 20% 8% 1	792
April	1st to 10th	Night	24% 16% 34% 22% 3	720
	11th to 20th	Night	22% 22% 28% 20% 7% 1	711
	21st to end	Night	24% 14% 28% 24% 10%	604
May	1st to 10th	Night	26% 9% 26% 29% 9% 2	394
	11th to 20th	Night	15% 10% 33% 34% 7%	354
	21st to end	Night	13% 7% 40% 27% 13% 1	389
June	1st to 10th	Night	17% 8% 37% 30% 9%	360
	11th to 20th	Night	14% 11% 32% 31% 12% 1	360
	21st to end	Night	16% 6% 28% 37% 12%	360
July	1st to 10th	Night	6% 8% 32% 37% 17% 1	350
	11th to 20th	Night	13% 3 27% 38% 19% 1	348
	21st to end	Night	12% 3 29% 43% 12% 1	394
August	1st to 10th	Night	12% 4 27% 33% 22% 1	501
	11th to 20th	Night	10% 5% 23% 35% 25% 3	534
	21st to end	Night	13% 6% 30% 31% 18% 2	756
September	1st to 10th	Night	13% 5% 33% 29% 17% 3	720
	11th to 20th	Night	14% 6% 25% 28% 23% 4	720
	21st to end	Night	18% 10% 24% 27% 18% 2	720
October	1st to 10th	Night	21% 15% 26% 23% 14% 2	720
	11th to 20th	Night	26% 15% 29% 22% 7% 1	720
	21st to end	Night	28% 15% 30% 22% 5%	792
November	1st to 10th	Night	25% 12% 30% 24% 8% 1	740
	11th to 20th	Night	25% 17% 33% 17% 7% 1	760
	21st to end	Night	29% 17% 29% 19% 6%	760
December	1st to 10th	Night	31% 18% 30% 18% 3	760
	11th to 20th	Night	26% 20% 34% 17% 2 1	760
	21st to end	Night	34% 16% 31% 16% 2	836

Page generated at 2024-02-02 05:20:31. Version ac07

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