Kennelly's Mountain
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Kennelly's Mountain clear sky chart from 2005-11-06 to 2024-02-20.

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% 6% 4 5% 5% 5% 6% 31%	78238
	Night	16% 11% 5% 8% 6% 4 5% 4 5% 6% 31%	80948
Transparency	Day	52% 7% 11% 18% 10% 1	77943
	Night	53% 7% 12% 18% 9% 1	80777
Seeing	Day	23% 18% 31% 18% 8% 3	13412
	Night	22% 16% 31% 23% 8% 1	22749

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	14% 15% 7% 12% 10% 4 4 5% 5% 4 20%	2517
	11th to 20th	Day	12% 13% 7% 14% 10% 5% 5% 5% 4 4 21%	2520
	21st to end	Day	16% 22% 7% 13% 7% 4 5% 3 3 4 17%	2996
February	1st to 10th	Day	12% 14% 7% 12% 9% 4 6% 5% 5% 5% 21%	1710
	11th to 20th	Day	11% 15% 5% 11% 8% 4 5% 4 5% 6% 27%	1654
	21st to end	Day	17% 15% 4 9% 7% 4 5% 5% 5% 4 24%	1440
March	1st to 10th	Day	14% 13% 5% 10% 8% 4 5% 5% 4 5% 27%	1854
	11th to 20th	Day	13% 14% 5% 8% 9% 5% 5% 5% 4 5% 28%	1980
	21st to end	Day	16% 11% 4 7% 5% 3 3 3 4 5% 37%	2253
April	1st to 10th	Day	21% 13% 4 6% 5% 3 4 4 4 6% 30%	2160
	11th to 20th	Day	21% 10% 3 6% 5% 3 4 4 3 4 38%	2134
	21st to end	Day	22% 10% 4 6% 5% 3 5% 3 4 5% 33%	2296
May	1st to 10th	Day	19% 8% 3 7% 5% 3 5% 5% 4 6% 36%	2515
	11th to 20th	Day	17% 7% 3 6% 5% 3 4 4 5% 7% 37%	2478
	21st to end	Day	14% 7% 3 6% 6% 4 5% 5% 6% 6% 38%	2725
June	1st to 10th	Day	22% 8% 4 6% 6% 3 5% 5% 5% 6% 31%	2520
	11th to 20th	Day	16% 6% 3 5% 5% 3 5% 5% 6% 8% 37%	2520
	21st to end	Day	17% 8% 3 6% 6% 4 4 5% 6% 8% 33%	2520
July	1st to 10th	Day	11% 6% 3 5% 7% 3 6% 5% 6% 8% 39%	2520
	11th to 20th	Day	12% 5% 3 5% 6% 4 6% 5% 7% 10% 37%	2520
	21st to end	Day	12% 5% 2 5% 6% 4 5% 7% 7% 9% 38%	2744
August	1st to 10th	Day	12% 6% 3 7% 6% 5% 6% 6% 5% 8% 37%	2400
	11th to 20th	Day	13% 6% 3 7% 7% 4 5% 6% 7% 7% 37%	2303
	21st to end	Day	14% 6% 3 6% 5% 3 5% 7% 6% 8% 37%	2394
September	1st to 10th	Day	15% 6% 3 5% 5% 3 5% 5% 6% 7% 40%	2160
	11th to 20th	Day	13% 6% 3 5% 5% 3 4 4 5% 7% 44%	2160
	21st to end	Day	17% 8% 3 5% 6% 3 5% 4 5% 7% 38%	1899
October	1st to 10th	Day	21% 9% 4 6% 5% 3 5% 4 5% 6% 34%	1800
	11th to 20th	Day	21% 11% 4 8% 6% 3 5% 5% 5% 6% 26%	1800
	21st to end	Day	26% 11% 3 7% 6% 4 4 4 5% 5% 23%	1886
November	1st to 10th	Day	14% 11% 4 6% 6% 3 5% 5% 4 7% 34%	1622
	11th to 20th	Day	16% 12% 6% 8% 7% 3 4 4 5% 5% 28%	1520
	21st to end	Day	19% 15% 6% 9% 7% 4 5% 4 5% 5% 19%	1520
December	1st to 10th	Day	20% 19% 6% 11% 9% 4 5% 4 4 4 15%	1520
	11th to 20th	Day	18% 14% 6% 10% 7% 3 4 4 4 5% 25%	1906
	21st to end	Day	26% 18% 6% 14% 6% 2 3 2 2 3 19%	2772
January	1st to 10th	Night	15% 15% 8% 12% 9% 4 4 5% 4 6% 17%	4429
	11th to 20th	Night	12% 12% 5% 12% 11% 6% 6% 5% 5% 6% 21%	4440
	21st to end	Night	15% 19% 8% 11% 8% 5% 5% 4 3 4 20%	4657
February	1st to 10th	Night	12% 14% 7% 10% 8% 5% 6% 5% 5% 6% 23%	2470
	11th to 20th	Night	12% 12% 7% 10% 7% 4 5% 4 4 6% 29%	2397
	21st to end	Night	14% 11% 5% 8% 8% 4 5% 4 6% 7% 28%	1816
March	1st to 10th	Night	15% 12% 6% 8% 8% 4 4 4 3 4 30%	2092
	11th to 20th	Night	13% 13% 6% 7% 6% 3 4 3 5% 6% 32%	1979
	21st to end	Night	14% 10% 4 7% 6% 3 5% 4 4 6% 37%	2102
April	1st to 10th	Night	19% 11% 3 6% 5% 4 4 4 4 6% 33%	1800
	11th to 20th	Night	18% 10% 3 6% 5% 4 3 4 3 6% 38%	1775
	21st to end	Night	20% 9% 4 7% 5% 3 5% 4 4 7% 32%	1679
May	1st to 10th	Night	19% 9% 3 5% 5% 3 4 4 4 7% 37%	1445
	11th to 20th	Night	17% 7% 2 5% 4 3 4 4 5% 6% 42%	1415
	21st to end	Night	12% 5% 3 4 4 2 4 5% 7% 9% 44%	1550
June	1st to 10th	Night	17% 5% 3 6% 6% 3 5% 5% 7% 7% 35%	1440
	11th to 20th	Night	13% 7% 3 6% 4 3 5% 5% 5% 6% 43%	1440
	21st to end	Night	16% 6% 2 5% 5% 3 4 4 5% 9% 38%	1440
July	1st to 10th	Night	9% 5% 3 6% 5% 3 5% 6% 6% 8% 46%	1440
	11th to 20th	Night	10% 5% 2 5% 5% 3 4 5% 7% 8% 44%	1440
	21st to end	Night	9% 5% 2 5% 5% 3 4 6% 7% 9% 45%	1574
August	1st to 10th	Night	9% 5% 2 5% 6% 4 6% 5% 6% 9% 43%	1534
	11th to 20th	Night	9% 6% 3 6% 5% 4 4 5% 6% 8% 47%	1598
	21st to end	Night	11% 7% 2 5% 4 4 4 4 5% 8% 45%	1943
September	1st to 10th	Night	11% 6% 3 4 5% 4 5% 5% 5% 7% 46%	1800
	11th to 20th	Night	15% 6% 1 4 4 3 4 4 4 6% 49%	1800
	21st to end	Night	15% 7% 2 5% 5% 3 4 5% 5% 7% 43%	2057
October	1st to 10th	Night	19% 8% 3 5% 5% 3 4 4 5% 6% 38%	2160
	11th to 20th	Night	20% 10% 3 7% 6% 4 5% 5% 5% 5% 30%	2160
	21st to end	Night	22% 12% 4 7% 6% 3 5% 4 5% 6% 26%	2470
November	1st to 10th	Night	16% 12% 4 7% 5% 3 4 4 5% 5% 35%	2454
	11th to 20th	Night	17% 12% 4 8% 7% 3 5% 4 5% 6% 28%	2660
	21st to end	Night	19% 16% 5% 9% 6% 3 4 4 5% 7% 22%	2660
December	1st to 10th	Night	18% 17% 7% 12% 7% 3 5% 5% 4 5% 18%	2660
	11th to 20th	Night	19% 16% 6% 9% 7% 3 4 3 3 4 25%	3288
	21st to end	Night	26% 18% 6% 12% 7% 3 4 3 3 3 15%	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	63% 11% 11% 8% 6% 1	2518
	11th to 20th	Day	65% 8% 9% 10% 6% 1	2520
	21st to end	Day	72% 6% 7% 9% 6% 1	2996
February	1st to 10th	Day	64% 7% 9% 14% 5% 1	1710
	11th to 20th	Day	57% 5% 12% 14% 9% 1	1663
	21st to end	Day	61% 7% 9% 12% 10% 2	1440
March	1st to 10th	Day	59% 6% 9% 15% 10% 2	1857
	11th to 20th	Day	57% 5% 10% 15% 10% 2	1980
	21st to end	Day	51% 4 8% 19% 13% 6%	2253
April	1st to 10th	Day	55% 6% 8% 17% 12% 3	2160
	11th to 20th	Day	49% 5% 7% 21% 15% 2	2134
	21st to end	Day	53% 6% 8% 15% 14% 4	2296
May	1st to 10th	Day	49% 7% 9% 17% 15% 4	2515
	11th to 20th	Day	46% 6% 10% 20% 16% 3	2482
	21st to end	Day	44% 8% 13% 19% 14% 3	2725
June	1st to 10th	Day	52% 8% 11% 17% 11% 1	2520
	11th to 20th	Day	43% 8% 11% 22% 14% 3	2520
	21st to end	Day	47% 9% 11% 20% 11% 1	2520
July	1st to 10th	Day	39% 8% 13% 26% 14% 1	2450
	11th to 20th	Day	39% 10% 16% 23% 11% 1	2445
	21st to end	Day	40% 10% 15% 25% 9%	2591
August	1st to 10th	Day	42% 10% 15% 22% 10%	2386
	11th to 20th	Day	43% 9% 18% 22% 8% 1	2303
	21st to end	Day	41% 9% 15% 24% 10% 1	2394
September	1st to 10th	Day	40% 9% 14% 25% 11%	2160
	11th to 20th	Day	37% 9% 12% 27% 14%	2160
	21st to end	Day	46% 7% 14% 24% 9%	1899
October	1st to 10th	Day	52% 6% 11% 20% 11% 1	1800
	11th to 20th	Day	57% 8% 13% 16% 5% 1	1800
	21st to end	Day	62% 7% 11% 14% 6% 1	1886
November	1st to 10th	Day	48% 8% 15% 21% 7% 1	1622
	11th to 20th	Day	58% 6% 13% 13% 9% 1	1520
	21st to end	Day	66% 8% 10% 10% 6% 1	1520
December	1st to 10th	Day	72% 7% 9% 9% 3	1520
	11th to 20th	Day	61% 8% 13% 12% 6% 1	1906
	21st to end	Day	73% 3 6% 13% 3	2772
January	1st to 10th	Night	66% 9% 12% 10% 3	4429
	11th to 20th	Night	61% 10% 14% 10% 4 1	4440
	21st to end	Night	69% 7% 8% 9% 6%	4657
February	1st to 10th	Night	61% 7% 11% 15% 6% 1	2470
	11th to 20th	Night	56% 6% 11% 19% 8% 1	2399
	21st to end	Night	55% 7% 10% 17% 10% 1	1816
March	1st to 10th	Night	57% 4 11% 16% 10% 2	2102
	11th to 20th	Night	52% 6% 11% 19% 11% 1	1980
	21st to end	Night	47% 6% 10% 20% 14% 4	2102
April	1st to 10th	Night	52% 5% 9% 19% 13% 2	1800
	11th to 20th	Night	48% 6% 8% 22% 15% 2	1775
	21st to end	Night	52% 6% 9% 15% 16% 2	1679
May	1st to 10th	Night	47% 6% 8% 19% 16% 4	1445
	11th to 20th	Night	41% 7% 10% 24% 17% 3	1416
	21st to end	Night	35% 9% 15% 20% 19% 2	1551
June	1st to 10th	Night	43% 9% 14% 22% 10% 1	1440
	11th to 20th	Night	39% 8% 11% 23% 16% 2	1440
	21st to end	Night	42% 8% 17% 19% 12% 1	1440
July	1st to 10th	Night	33% 10% 13% 24% 18% 2	1400
	11th to 20th	Night	37% 7% 15% 29% 12%	1392
	21st to end	Night	33% 9% 18% 26% 13% 1	1486
August	1st to 10th	Night	36% 10% 19% 23% 12% 1	1524
	11th to 20th	Night	34% 10% 17% 28% 10% 1	1598
	21st to end	Night	36% 8% 16% 29% 10% 1	1943
September	1st to 10th	Night	35% 9% 15% 26% 14% 1	1800
	11th to 20th	Night	35% 7% 15% 32% 10% 1	1800
	21st to end	Night	40% 7% 14% 31% 8%	2057
October	1st to 10th	Night	46% 7% 12% 20% 14%	2160
	11th to 20th	Night	54% 9% 12% 17% 8%	2160
	21st to end	Night	58% 8% 12% 15% 8%	2470
November	1st to 10th	Night	49% 7% 15% 20% 9%	2454
	11th to 20th	Night	56% 8% 12% 16% 8% 1	2660
	21st to end	Night	61% 8% 12% 14% 4	2660
December	1st to 10th	Night	68% 7% 10% 12% 3	2660
	11th to 20th	Night	63% 6% 10% 13% 7% 1	3288
	21st to end	Night	74% 6% 7% 11% 2	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	24% 21% 37% 13% 4 1	180
	11th to 20th	Day	29% 22% 35% 11% 3	180
	21st to end	Day	23% 23% 36% 13% 4 1	261
February	1st to 10th	Day	30% 27% 31% 9% 3	270
	11th to 20th	Day	31% 26% 38% 4 1	267
	21st to end	Day	34% 26% 30% 8% 1	306
March	1st to 10th	Day	25% 22% 36% 13% 2	420
	11th to 20th	Day	28% 21% 33% 14% 3 1	420
	21st to end	Day	32% 22% 27% 13% 6%	462
April	1st to 10th	Day	31% 21% 30% 12% 6%	420
	11th to 20th	Day	33% 22% 18% 17% 8% 1	412
	21st to end	Day	32% 18% 31% 11% 7% 1	420
May	1st to 10th	Day	26% 18% 30% 17% 6% 3	423
	11th to 20th	Day	21% 18% 32% 20% 6% 2	447
	21st to end	Day	18% 17% 35% 19% 7% 4	485
June	1st to 10th	Day	25% 14% 35% 19% 7%	450
	11th to 20th	Day	17% 15% 31% 22% 12% 2	450
	21st to end	Day	18% 15% 34% 21% 10% 2	450
July	1st to 10th	Day	10% 8% 34% 35% 10% 3	445
	11th to 20th	Day	14% 12% 32% 28% 12% 3	444
	21st to end	Day	15% 9% 37% 26% 10% 3	488
August	1st to 10th	Day	15% 7% 33% 28% 12% 5%	446
	11th to 20th	Day	11% 11% 29% 28% 14% 6%	439
	21st to end	Day	15% 14% 31% 23% 11% 7%	495
September	1st to 10th	Day	15% 13% 31% 21% 14% 7%	450
	11th to 20th	Day	13% 13% 27% 23% 14% 9%	450
	21st to end	Day	18% 16% 30% 18% 12% 6%	450
October	1st to 10th	Day	25% 19% 22% 20% 10% 4	450
	11th to 20th	Day	28% 23% 30% 13% 4 2	450
	21st to end	Day	31% 18% 30% 16% 4	448
November	1st to 10th	Day	26% 20% 31% 16% 7% 1	316
	11th to 20th	Day	29% 24% 29% 10% 5% 2	180
	21st to end	Day	32% 23% 35% 7% 3 1	180
December	1st to 10th	Day	31% 18% 37% 13% 1	180
	11th to 20th	Day	32% 29% 27% 8% 2 1	180
	21st to end	Day	30% 26% 29% 11% 3 1	198
January	1st to 10th	Night	25% 22% 33% 16% 3	760
	11th to 20th	Night	26% 22% 29% 18% 5% 1	760
	21st to end	Night	18% 17% 38% 22% 4	836
February	1st to 10th	Night	21% 21% 37% 19% 2	760
	11th to 20th	Night	20% 22% 42% 13% 3	742
	21st to end	Night	23% 22% 33% 20% 3	592
March	1st to 10th	Night	25% 19% 35% 18% 3	720
	11th to 20th	Night	24% 22% 31% 18% 4 1	720
	21st to end	Night	23% 17% 31% 22% 7% 1	792
April	1st to 10th	Night	28% 17% 32% 20% 4	720
	11th to 20th	Night	23% 22% 29% 18% 7%	711
	21st to end	Night	24% 16% 28% 24% 8% 1	599
May	1st to 10th	Night	23% 11% 28% 27% 10% 1	365
	11th to 20th	Night	22% 10% 32% 27% 7%	354
	21st to end	Night	14% 10% 36% 30% 10%	389
June	1st to 10th	Night	16% 9% 38% 31% 7%	360
	11th to 20th	Night	15% 12% 33% 30% 10% 1	360
	21st to end	Night	19% 9% 29% 29% 13%	360
July	1st to 10th	Night	7% 10% 33% 37% 12% 1	350
	11th to 20th	Night	11% 7% 29% 41% 13%	348
	21st to end	Night	9% 5% 33% 41% 12%	394
August	1st to 10th	Night	11% 6% 25% 40% 18%	460
	11th to 20th	Night	11% 3 25% 38% 20% 3	534
	21st to end	Night	14% 8% 31% 29% 16% 2	755
September	1st to 10th	Night	14% 9% 31% 29% 16% 2	720
	11th to 20th	Night	18% 7% 24% 30% 18% 3	720
	21st to end	Night	20% 12% 23% 25% 18% 2	720
October	1st to 10th	Night	23% 14% 27% 24% 11% 2	720
	11th to 20th	Night	26% 15% 33% 18% 7% 1	720
	21st to end	Night	29% 17% 30% 20% 5%	792
November	1st to 10th	Night	25% 16% 31% 22% 5% 1	740
	11th to 20th	Night	23% 22% 32% 14% 8% 1	760
	21st to end	Night	31% 18% 27% 19% 4	760
December	1st to 10th	Night	29% 21% 32% 16% 3	760
	11th to 20th	Night	28% 22% 30% 18% 2 1	760
	21st to end	Night	32% 18% 32% 15% 3	836

Page generated at 2024-02-17 06:28:35. Version ac07

Copyright 2024 Attilla Danko