Conconully
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Conconully clear sky chart from 2005-11-06 to 2024-01-13.

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	9% 9% 4 7% 6% 4 5% 5% 5% 7% 39%	74714
	Night	9% 9% 4 7% 6% 3 5% 5% 6% 7% 40%	74999
Transparency	Day	38% 7% 14% 22% 14% 4	74417
	Night	41% 8% 14% 21% 12% 3	74814
Seeing	Day	12% 15% 32% 26% 12% 2	13340
	Night	12% 6% 26% 36% 18% 2	22472

By Month

Percentage Cloud Cover NW (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% 17% 7% 10% 7% 4 4 5% 5% 7% 21%	1519
	11th to 20th	Day	11% 13% 4 8% 7% 4 4 5% 5% 7% 33%	1456
	21st to end	Day	8% 15% 7% 8% 5% 3 4 4 5% 8% 34%	1584
February	1st to 10th	Day	8% 11% 5% 11% 7% 4 5% 7% 5% 7% 30%	1521
	11th to 20th	Day	7% 14% 5% 7% 5% 3 4 6% 5% 8% 37%	1575
	21st to end	Day	7% 12% 6% 10% 8% 4 5% 5% 7% 9% 28%	1476
March	1st to 10th	Day	9% 14% 6% 8% 6% 5% 5% 5% 5% 8% 30%	1800
	11th to 20th	Day	10% 11% 4 7% 6% 4 6% 7% 7% 8% 30%	1892
	21st to end	Day	11% 14% 5% 7% 7% 5% 7% 6% 7% 7% 24%	2341
April	1st to 10th	Day	10% 10% 5% 8% 8% 5% 7% 7% 6% 8% 27%	2160
	11th to 20th	Day	8% 12% 5% 7% 7% 4 6% 6% 7% 8% 30%	2132
	21st to end	Day	8% 11% 3 8% 7% 4 6% 6% 6% 8% 33%	2423
May	1st to 10th	Day	8% 9% 4 7% 6% 4 6% 6% 7% 8% 34%	2520
	11th to 20th	Day	12% 9% 4 7% 7% 4 6% 6% 7% 8% 31%	2477
	21st to end	Day	13% 8% 3 8% 7% 4 6% 6% 6% 7% 31%	2723
June	1st to 10th	Day	15% 8% 4 6% 6% 4 6% 7% 5% 7% 33%	2520
	11th to 20th	Day	12% 8% 3 8% 6% 5% 8% 6% 5% 6% 33%	2520
	21st to end	Day	8% 6% 2 5% 6% 3 5% 5% 6% 7% 47%	2698
July	1st to 10th	Day	5% 5% 2 4 5% 4 5% 5% 7% 7% 53%	2543
	11th to 20th	Day	4 4 2 4 4 3 5% 4 5% 5% 59%	2520
	21st to end	Day	3 2 1 3 3 2 3 4 5% 6% 69%	2741
August	1st to 10th	Day	4 3 1 4 5% 2 4 4 5% 7% 61%	2507
	11th to 20th	Day	4 4 1 4 3 3 4 3 4 6% 63%	2421
	21st to end	Day	4 5% 2 6% 5% 4 5% 5% 5% 7% 51%	2386
September	1st to 10th	Day	6% 4 2 4 5% 2 4 4 4 6% 59%	2160
	11th to 20th	Day	7% 5% 3 5% 6% 4 5% 5% 5% 7% 49%	2144
	21st to end	Day	9% 6% 2 6% 5% 2 4 5% 4 6% 50%	1962
October	1st to 10th	Day	9% 6% 3 6% 5% 4 4 6% 5% 6% 47%	1800
	11th to 20th	Day	9% 7% 3 7% 5% 4 5% 5% 5% 7% 42%	1773
	21st to end	Day	13% 10% 4 6% 5% 3 5% 5% 5% 6% 38%	1782
November	1st to 10th	Day	14% 11% 4 7% 7% 4 6% 5% 6% 7% 30%	1621
	11th to 20th	Day	12% 12% 4 8% 6% 2 4 5% 5% 6% 35%	1520
	21st to end	Day	9% 11% 5% 9% 6% 4 6% 5% 6% 6% 32%	1520
December	1st to 10th	Day	10% 10% 5% 7% 7% 4 6% 4 6% 6% 35%	1406
	11th to 20th	Day	12% 15% 5% 10% 8% 4 6% 6% 5% 6% 24%	1777
	21st to end	Day	12% 17% 8% 11% 8% 4 5% 5% 6% 5% 20%	2794
January	1st to 10th	Night	13% 16% 5% 10% 8% 4 6% 6% 5% 6% 23%	2646
	11th to 20th	Night	12% 12% 5% 9% 7% 3 4 4 6% 9% 28%	2548
	21st to end	Night	10% 12% 5% 9% 7% 3 5% 5% 6% 9% 32%	2772
February	1st to 10th	Night	9% 11% 4 7% 6% 3 6% 6% 6% 8% 33%	2435
	11th to 20th	Night	8% 9% 4 7% 7% 4 4 4 5% 9% 39%	2272
	21st to end	Night	7% 10% 5% 9% 6% 4 5% 6% 7% 8% 33%	1779
March	1st to 10th	Night	9% 11% 5% 6% 6% 4 6% 7% 7% 7% 33%	2160
	11th to 20th	Night	8% 9% 3 8% 7% 4 6% 5% 6% 8% 36%	2065
	21st to end	Night	8% 11% 4 8% 8% 4 6% 6% 6% 7% 31%	2014
April	1st to 10th	Night	8% 9% 4 9% 7% 4 7% 5% 6% 8% 34%	1800
	11th to 20th	Night	7% 9% 4 7% 6% 4 5% 5% 5% 6% 41%	1779
	21st to end	Night	7% 9% 3 5% 6% 3 5% 5% 8% 7% 42%	1536
May	1st to 10th	Night	6% 6% 2 5% 6% 4 5% 6% 5% 7% 46%	1440
	11th to 20th	Night	10% 7% 3 5% 5% 3 5% 7% 7% 8% 40%	1416
	21st to end	Night	12% 6% 3 4 5% 3 5% 7% 7% 8% 40%	1552
June	1st to 10th	Night	10% 7% 3 6% 5% 4 6% 5% 8% 7% 39%	1440
	11th to 20th	Night	8% 6% 3 5% 6% 4 4 6% 5% 8% 46%	1432
	21st to end	Night	5% 4 2 4 5% 3 4 4 6% 8% 57%	1260
July	1st to 10th	Night	5% 3 1 4 4 3 4 6% 6% 5% 59%	1408
	11th to 20th	Night	2 2 1 3 4 2 3 5% 6% 8% 65%	1440
	21st to end	Night	1 1 1 3 2 2 3 3 4 6% 74%	1576
August	1st to 10th	Night	4 3 2 3 3 2 3 2 4 6% 69%	1432
	11th to 20th	Night	2 2 2 3 3 2 3 3 5% 7% 68%	1475
	21st to end	Night	4 3 2 3 4 3 4 3 5% 7% 61%	1968
September	1st to 10th	Night	5% 3 1 4 3 2 4 5% 5% 6% 61%	1800
	11th to 20th	Night	7% 4 2 4 4 2 3 4 6% 6% 58%	1815
	21st to end	Night	7% 5% 2 4 5% 3 4 5% 6% 7% 52%	1996
October	1st to 10th	Night	10% 7% 2 5% 5% 3 4 5% 6% 6% 49%	2160
	11th to 20th	Night	9% 6% 2 6% 6% 3 4 4 6% 6% 46%	2186
	21st to end	Night	13% 9% 3 6% 6% 4 4 5% 5% 6% 40%	2574
November	1st to 10th	Night	16% 10% 4 6% 5% 4 5% 5% 6% 7% 33%	2457
	11th to 20th	Night	12% 10% 4 6% 5% 4 5% 5% 5% 7% 37%	2660
	21st to end	Night	10% 13% 4 9% 7% 5% 5% 6% 5% 6% 30%	2660
December	1st to 10th	Night	9% 13% 5% 8% 5% 3 4 5% 6% 7% 34%	2746
	11th to 20th	Night	11% 16% 5% 10% 8% 4 5% 5% 6% 8% 22%	3438
	21st to end	Night	13% 18% 6% 10% 6% 3 4 4 5% 5% 25%	4862

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	65% 12% 11% 9% 3	1519
	11th to 20th	Day	56% 12% 14% 14% 3 2	1456
	21st to end	Day	53% 12% 14% 16% 5%	1584
February	1st to 10th	Day	48% 12% 18% 16% 5% 1	1521
	11th to 20th	Day	42% 11% 20% 18% 9%	1584
	21st to end	Day	45% 12% 18% 17% 8%	1476
March	1st to 10th	Day	47% 9% 18% 16% 9% 1	1800
	11th to 20th	Day	43% 7% 19% 22% 9%	1892
	21st to end	Day	47% 9% 19% 18% 6% 1	2341
April	1st to 10th	Day	45% 9% 16% 22% 7% 2	2160
	11th to 20th	Day	41% 7% 17% 22% 12% 2	2132
	21st to end	Day	39% 8% 15% 23% 12% 3	2423
May	1st to 10th	Day	36% 6% 17% 27% 12% 2	2520
	11th to 20th	Day	38% 6% 19% 24% 12% 1	2480
	21st to end	Day	41% 8% 15% 25% 9% 1	2724
June	1st to 10th	Day	42% 5% 13% 20% 14% 5%	2520
	11th to 20th	Day	40% 6% 17% 22% 13% 3	2520
	21st to end	Day	28% 4 15% 28% 20% 5%	2698
July	1st to 10th	Day	21% 5% 12% 26% 25% 11%	2474
	11th to 20th	Day	20% 4 8% 23% 29% 17%	2445
	21st to end	Day	12% 3 5% 26% 37% 17%	2589
August	1st to 10th	Day	17% 4 9% 28% 29% 13%	2490
	11th to 20th	Day	16% 3 11% 29% 33% 8%	2421
	21st to end	Day	23% 6% 12% 32% 23% 4	2386
September	1st to 10th	Day	20% 5% 13% 29% 26% 6%	2160
	11th to 20th	Day	29% 7% 13% 23% 23% 6%	2144
	21st to end	Day	29% 6% 17% 28% 17% 3	1962
October	1st to 10th	Day	31% 7% 16% 29% 15% 1	1800
	11th to 20th	Day	34% 9% 20% 24% 12% 1	1773
	21st to end	Day	43% 10% 14% 22% 10%	1782
November	1st to 10th	Day	48% 11% 15% 15% 10% 1	1621
	11th to 20th	Day	50% 10% 16% 17% 6% 1	1520
	21st to end	Day	53% 11% 15% 13% 6% 1	1520
December	1st to 10th	Day	52% 12% 14% 17% 5%	1406
	11th to 20th	Day	65% 10% 12% 9% 4	1780
	21st to end	Day	67% 9% 9% 10% 4	2794
January	1st to 10th	Night	64% 11% 11% 9% 5%	2646
	11th to 20th	Night	58% 10% 14% 14% 4 1	2548
	21st to end	Night	58% 10% 15% 11% 5% 1	2772
February	1st to 10th	Night	51% 12% 17% 13% 6% 1	2435
	11th to 20th	Night	42% 12% 19% 20% 7%	2274
	21st to end	Night	44% 12% 17% 17% 9% 1	1779
March	1st to 10th	Night	44% 10% 18% 19% 8% 1	2160
	11th to 20th	Night	41% 8% 16% 25% 9% 1	2066
	21st to end	Night	45% 8% 19% 21% 6% 1	2014
April	1st to 10th	Night	41% 8% 17% 24% 8% 2	1800
	11th to 20th	Night	37% 6% 15% 23% 16% 3	1779
	21st to end	Night	34% 7% 14% 28% 14% 3	1536
May	1st to 10th	Night	31% 5% 16% 30% 15% 3	1440
	11th to 20th	Night	34% 6% 18% 27% 12% 2	1416
	21st to end	Night	34% 9% 16% 27% 12% 1	1552
June	1st to 10th	Night	35% 7% 13% 24% 17% 5%	1440
	11th to 20th	Night	32% 7% 16% 28% 15% 2	1432
	21st to end	Night	21% 6% 16% 30% 22% 5%	1260
July	1st to 10th	Night	20% 5% 9% 28% 24% 13%	1368
	11th to 20th	Night	14% 5% 10% 27% 28% 16%	1392
	21st to end	Night	8% 4 7% 26% 35% 19%	1488
August	1st to 10th	Night	15% 4 11% 24% 29% 16%	1424
	11th to 20th	Night	12% 4 11% 29% 37% 7%	1475
	21st to end	Night	19% 4 11% 30% 30% 6%	1968
September	1st to 10th	Night	19% 4 13% 30% 28% 7%	1800
	11th to 20th	Night	23% 5% 13% 26% 26% 7%	1815
	21st to end	Night	26% 6% 16% 32% 16% 5%	1996
October	1st to 10th	Night	31% 6% 16% 29% 17% 1	2160
	11th to 20th	Night	34% 9% 17% 27% 13% 1	2186
	21st to end	Night	40% 8% 14% 28% 10%	2574
November	1st to 10th	Night	46% 9% 19% 16% 8% 1	2457
	11th to 20th	Night	46% 12% 18% 15% 6% 2	2660
	21st to end	Night	57% 11% 14% 12% 6%	2660
December	1st to 10th	Night	54% 10% 15% 18% 3	2746
	11th to 20th	Night	68% 9% 10% 9% 4	3434
	21st to end	Night	65% 9% 10% 11% 5% 1	4862

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	16% 16% 31% 19% 13% 6%	180
	11th to 20th	Day	21% 13% 23% 23% 15% 4	164
	21st to end	Day	20% 9% 28% 31% 10% 2	176
February	1st to 10th	Day	10% 15% 46% 22% 7%	241
	11th to 20th	Day	13% 17% 37% 26% 6% 1	335
	21st to end	Day	8% 18% 38% 26% 9% 1	344
March	1st to 10th	Day	16% 19% 38% 18% 8% 1	420
	11th to 20th	Day	16% 23% 27% 20% 14% 1	420
	21st to end	Day	17% 21% 32% 21% 8%	462
April	1st to 10th	Day	21% 20% 31% 19% 8% 1	420
	11th to 20th	Day	17% 26% 28% 18% 8% 4	412
	21st to end	Day	15% 21% 30% 23% 10% 2	420
May	1st to 10th	Day	12% 18% 35% 28% 6% 1	423
	11th to 20th	Day	19% 12% 26% 27% 13% 3	448
	21st to end	Day	15% 13% 27% 28% 14% 4	485
June	1st to 10th	Day	15% 17% 35% 23% 8% 2	450
	11th to 20th	Day	15% 21% 33% 22% 8% 1	450
	21st to end	Day	9% 11% 35% 28% 16% 1	628
July	1st to 10th	Day	5% 10% 35% 37% 12% 1	469
	11th to 20th	Day	7% 15% 33% 29% 13% 2	444
	21st to end	Day	5% 10% 33% 33% 17% 3	487
August	1st to 10th	Day	5% 9% 29% 35% 18% 4	447
	11th to 20th	Day	4 7% 29% 32% 23% 5%	437
	21st to end	Day	7% 12% 33% 30% 14% 4	495
September	1st to 10th	Day	8% 12% 35% 27% 14% 4	450
	11th to 20th	Day	10% 13% 30% 28% 15% 4	450
	21st to end	Day	12% 17% 32% 26% 10% 3	450
October	1st to 10th	Day	11% 15% 35% 23% 16% 1	450
	11th to 20th	Day	11% 18% 31% 24% 13% 3	423
	21st to end	Day	14% 18% 31% 24% 11% 2	297
November	1st to 10th	Day	17% 15% 28% 30% 9% 1	245
	11th to 20th	Day	12% 21% 31% 22% 12% 2	180
	21st to end	Day	13% 13% 32% 26% 13% 3	180
December	1st to 10th	Day	16% 10% 26% 21% 19% 8%	180
	11th to 20th	Day	11% 11% 37% 31% 8% 3	180
	21st to end	Day	11% 9% 32% 34% 12% 2	198
January	1st to 10th	Night	18% 9% 32% 26% 13% 2	760
	11th to 20th	Night	18% 8% 25% 33% 14% 2	728
	21st to end	Night	13% 5% 30% 34% 16% 1	792
February	1st to 10th	Night	14% 6% 34% 34% 10% 2	720
	11th to 20th	Night	12% 7% 31% 36% 14% 1	704
	21st to end	Night	11% 9% 29% 32% 17% 3	592
March	1st to 10th	Night	13% 5% 29% 35% 16% 2	720
	11th to 20th	Night	11% 8% 28% 35% 16% 2	720
	21st to end	Night	11% 6% 30% 39% 13% 2	792
April	1st to 10th	Night	12% 6% 26% 38% 18% 1	720
	11th to 20th	Night	10% 6% 29% 37% 16% 2	711
	21st to end	Night	8% 7% 36% 33% 14%	456
May	1st to 10th	Night	7% 6% 33% 35% 18% 1	360
	11th to 20th	Night	12% 4 19% 39% 24% 2	354
	21st to end	Night	13% 4 19% 37% 24% 3	389
June	1st to 10th	Night	11% 6% 26% 39% 18% 1	360
	11th to 20th	Night	9% 6% 29% 36% 18% 1	360
	21st to end	Night	4 3 27% 37% 26% 2	360
July	1st to 10th	Night	6% 4 18% 42% 29% 1	350
	11th to 20th	Night	3 4 26% 43% 23% 1	348
	21st to end	Night	1 1 20% 44% 33% 2	394
August	1st to 10th	Night	4 4 16% 37% 36% 3	358
	11th to 20th	Night	3 2 18% 36% 37% 4	407
	21st to end	Night	6% 5% 20% 41% 26% 2	780
September	1st to 10th	Night	6% 4 21% 41% 24% 4	720
	11th to 20th	Night	8% 4 17% 31% 33% 8%	720
	21st to end	Night	9% 5% 23% 34% 24% 4	720
October	1st to 10th	Night	13% 4 20% 36% 25% 2	720
	11th to 20th	Night	10% 5% 26% 39% 18% 3	720
	21st to end	Night	18% 8% 26% 33% 12% 3	792
November	1st to 10th	Night	20% 6% 28% 37% 9%	740
	11th to 20th	Night	16% 10% 28% 32% 13% 2	760
	21st to end	Night	16% 7% 29% 30% 14% 3	760
December	1st to 10th	Night	14% 6% 26% 37% 15% 2	846
	11th to 20th	Night	18% 7% 30% 34% 9% 1	903
	21st to end	Night	19% 8% 27% 37% 7%	836

Page generated at 2024-01-09 22:25:03. Version ac07

Copyright 2024 Attilla Danko