Cuesta College - North County Campus
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Cuesta College - North County Campus clear sky chart from 2005-11-06 to 2024-01-16.

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	4 3 2 3 3 2 3 3 4 6% 66%	74748
	Night	4 3 2 4 4 2 3 4 4 6% 64%	75070
Transparency	Day	20% 3 7% 18% 28% 23%	74468
	Night	22% 3 8% 19% 27% 22%	74872
Seeing	Day	5% 5% 17% 31% 29% 13%	14392
	Night	5% 3 12% 37% 36% 7%	24041

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	8% 7% 2 5% 6% 4 6% 6% 6% 7% 44%	1609
	11th to 20th	Day	6% 4 2 4 4 3 4 4 5% 7% 57%	1669
	21st to end	Day	10% 5% 2 5% 5% 4 4 5% 4 8% 48%	1782
February	1st to 10th	Day	9% 5% 2 5% 3 2 4 4 4 6% 55%	1672
	11th to 20th	Day	7% 4 2 5% 4 3 4 5% 5% 7% 53%	1750
	21st to end	Day	8% 6% 3 4 4 2 4 5% 5% 7% 52%	1480
March	1st to 10th	Day	6% 5% 3 6% 6% 4 6% 6% 6% 9% 42%	1854
	11th to 20th	Day	8% 5% 3 4 6% 4 6% 5% 6% 8% 46%	1980
	21st to end	Day	6% 4 2 5% 4 3 4 5% 5% 6% 56%	2272
April	1st to 10th	Day	6% 5% 3 5% 4 2 3 5% 5% 8% 55%	2160
	11th to 20th	Day	4 4 2 4 4 2 3 4 5% 8% 60%	2129
	21st to end	Day	4 3 2 3 3 2 3 4 4 7% 66%	2160
May	1st to 10th	Day	3 3 1 3 3 2 3 2 4 6% 70%	2160
	11th to 20th	Day	2 2 1 2 2 1 3 3 4 7% 72%	2228
	21st to end	Day	2 3 2 2 3 1 2 2 4 7% 72%	2723
June	1st to 10th	Day	2 2 1 2 3 1 3 3 4 8% 71%	2520
	11th to 20th	Day	1 1 2 2 1 2 2 2 4 85%	2520
	21st to end	Day	1 1 1 2 1 2 1 3 4 85%	2520
July	1st to 10th	Day	1 1 2 1 1 2 2 3 4 84%	2520
	11th to 20th	Day	1 1 1 2 2 2 2 3 3 5% 79%	2372
	21st to end	Day	1 1 2 2 2 3 3 4 6% 75%	2546
August	1st to 10th	Day	1 1 2 2 1 3 3 3 5% 79%	2240
	11th to 20th	Day	1 1 1 2 2 1 1 2 2 4 84%	2122
	21st to end	Day	1 2 2 2 2 2 2 2 4 80%	2376
September	1st to 10th	Day	1 1 1 1 1 1 2 3 5% 83%	2160
	11th to 20th	Day	1 1 1 2 2 2 1 2 3 5% 80%	2160
	21st to end	Day	1 2 1 2 2 2 2 3 4 5% 76%	1976
October	1st to 10th	Day	2 2 1 3 2 2 3 3 4 6% 72%	1800
	11th to 20th	Day	2 2 1 3 3 2 3 4 4 6% 71%	1800
	21st to end	Day	2 3 1 3 3 2 3 3 4 6% 70%	1980
November	1st to 10th	Day	3 3 2 3 3 3 4 4 4 6% 64%	1779
	11th to 20th	Day	4 3 2 4 4 3 3 5% 4 7% 62%	1710
	21st to end	Day	4 4 2 4 4 2 4 4 5% 6% 61%	1710
December	1st to 10th	Day	6% 5% 3 6% 6% 3 4 4 5% 7% 51%	1587
	11th to 20th	Day	14% 9% 3 7% 7% 4 4 4 5% 7% 36%	1928
	21st to end	Day	12% 7% 3 7% 5% 3 5% 5% 6% 8% 38%	2794
January	1st to 10th	Night	8% 6% 3 5% 6% 4 4 5% 5% 7% 46%	2551
	11th to 20th	Night	5% 4 2 5% 4 3 5% 5% 6% 7% 55%	2418
	21st to end	Night	9% 4 3 5% 3 2 4 4 5% 7% 55%	2574
February	1st to 10th	Night	7% 5% 2 3 4 2 5% 4 3 7% 57%	2286
	11th to 20th	Night	6% 3 2 3 4 2 3 4 5% 8% 60%	2098
	21st to end	Night	8% 3 2 4 5% 2 4 3 4 5% 59%	1776
March	1st to 10th	Night	7% 6% 3 4 5% 3 5% 5% 6% 7% 50%	2102
	11th to 20th	Night	6% 4 2 5% 5% 3 4 5% 6% 8% 51%	1980
	21st to end	Night	6% 3 2 4 4 2 4 4 4 7% 60%	2084
April	1st to 10th	Night	5% 3 1 3 4 2 3 5% 4 7% 61%	1800
	11th to 20th	Night	3 4 2 3 3 2 3 4 3 5% 69%	1779
	21st to end	Night	3 2 2 3 3 2 3 4 4 7% 68%	1800
May	1st to 10th	Night	2 2 1 2 3 2 2 3 4 8% 71%	1800
	11th to 20th	Night	2 2 1 2 2 2 2 3 4 6% 74%	1657
	21st to end	Night	1 3 1 2 4 1 3 3 3 7% 72%	1552
June	1st to 10th	Night	2 1 1 2 2 2 3 4 4 6% 73%	1440
	11th to 20th	Night	1 1 1 2 1 1 2 3 5% 83%	1440
	21st to end	Night	1 1 1 1 1 2 4 88%	1440
July	1st to 10th	Night	2 1 1 2 3 4 5% 82%	1440
	11th to 20th	Night	1 1 1 1 1 2 2 3 3 4 83%	1584
	21st to end	Night	1 1 1 1 2 2 2 4 4 6% 75%	1773
August	1st to 10th	Night	1 1 1 2 2 2 2 2 3 3 81%	1695
	11th to 20th	Night	2 1 1 2 2 3 4 83%	1780
	21st to end	Night	1 1 2 1 2 2 2 5% 82%	1980
September	1st to 10th	Night	1 1 1 1 2 1 2 2 2 4 83%	1800
	11th to 20th	Night	1 2 1 2 2 1 2 3 3 4 80%	1800
	21st to end	Night	1 2 1 1 2 1 2 3 3 4 82%	1981
October	1st to 10th	Night	2 2 1 2 3 1 3 4 3 6% 73%	2160
	11th to 20th	Night	2 3 2 3 4 2 3 3 4 5% 70%	2160
	21st to end	Night	3 4 1 3 3 2 2 3 3 5% 71%	2376
November	1st to 10th	Night	3 2 2 3 3 2 3 3 4 6% 69%	2298
	11th to 20th	Night	3 3 2 3 4 2 4 4 5% 6% 65%	2470
	21st to end	Night	4 4 2 4 4 2 4 4 6% 7% 60%	2470
December	1st to 10th	Night	8% 5% 2 5% 4 3 4 4 4 7% 53%	2588
	11th to 20th	Night	12% 8% 4 7% 6% 4 5% 5% 6% 7% 36%	3276
	21st to end	Night	10% 7% 3 8% 7% 4 6% 5% 5% 6% 37%	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	37% 5% 11% 22% 20% 6%	1609
	11th to 20th	Day	28% 3 11% 22% 20% 15%	1669
	21st to end	Day	35% 4 12% 17% 20% 12%	1782
February	1st to 10th	Day	31% 2 7% 20% 24% 15%	1672
	11th to 20th	Day	30% 3 9% 22% 26% 10%	1760
	21st to end	Day	33% 4 11% 22% 24% 7%	1480
March	1st to 10th	Day	38% 5% 11% 18% 19% 8%	1854
	11th to 20th	Day	35% 5% 12% 21% 20% 8%	1980
	21st to end	Day	29% 5% 12% 28% 19% 7%	2272
April	1st to 10th	Day	28% 5% 10% 25% 21% 10%	2160
	11th to 20th	Day	23% 4 11% 27% 26% 9%	2132
	21st to end	Day	19% 4 10% 26% 31% 9%	2160
May	1st to 10th	Day	18% 3 10% 21% 37% 12%	2160
	11th to 20th	Day	13% 4 6% 27% 37% 12%	2231
	21st to end	Day	15% 4 9% 31% 34% 8%	2724
June	1st to 10th	Day	14% 3 10% 20% 34% 19%	2520
	11th to 20th	Day	8% 1 5% 13% 42% 31%	2520
	21st to end	Day	7% 2 2 10% 35% 44%	2520
July	1st to 10th	Day	6% 1 1 7% 30% 54%	2451
	11th to 20th	Day	8% 3 3 9% 30% 47%	2301
	21st to end	Day	10% 3 3 12% 28% 44%	2405
August	1st to 10th	Day	10% 2 2 9% 29% 49%	2224
	11th to 20th	Day	8% 1 2 10% 33% 46%	2122
	21st to end	Day	10% 2 1 9% 37% 42%	2376
September	1st to 10th	Day	7% 2 2 9% 30% 49%	2160
	11th to 20th	Day	10% 1 2 17% 40% 30%	2160
	21st to end	Day	10% 2 2 18% 39% 28%	1976
October	1st to 10th	Day	15% 3 5% 21% 24% 32%	1800
	11th to 20th	Day	16% 3 5% 18% 29% 28%	1800
	21st to end	Day	17% 3 5% 17% 30% 28%	1980
November	1st to 10th	Day	21% 3 8% 20% 31% 18%	1779
	11th to 20th	Day	22% 4 10% 21% 27% 16%	1710
	21st to end	Day	25% 3 7% 19% 26% 20%	1710
December	1st to 10th	Day	32% 5% 8% 20% 20% 16%	1587
	11th to 20th	Day	47% 5% 9% 17% 15% 8%	1928
	21st to end	Day	41% 5% 13% 23% 13% 5%	2794
January	1st to 10th	Night	36% 4 11% 22% 22% 6%	2551
	11th to 20th	Night	29% 4 11% 22% 19% 16%	2418
	21st to end	Night	30% 4 12% 18% 22% 13%	2574
February	1st to 10th	Night	31% 2 8% 20% 26% 14%	2286
	11th to 20th	Night	24% 3 9% 24% 30% 11%	2099
	21st to end	Night	28% 4 10% 25% 25% 8%	1776
March	1st to 10th	Night	33% 5% 13% 23% 18% 8%	2102
	11th to 20th	Night	29% 6% 12% 20% 24% 8%	1980
	21st to end	Night	26% 4 15% 26% 22% 7%	2084
April	1st to 10th	Night	23% 4 14% 28% 19% 12%	1800
	11th to 20th	Night	19% 3 11% 30% 26% 11%	1779
	21st to end	Night	18% 4 8% 29% 34% 8%	1800
May	1st to 10th	Night	14% 3 11% 25% 32% 15%	1800
	11th to 20th	Night	13% 2 7% 27% 39% 12%	1658
	21st to end	Night	15% 3 10% 29% 33% 10%	1552
June	1st to 10th	Night	13% 3 13% 20% 33% 19%	1440
	11th to 20th	Night	8% 1 5% 15% 40% 30%	1440
	21st to end	Night	4 2 2 9% 37% 46%	1440
July	1st to 10th	Night	6% 1 2 7% 26% 57%	1400
	11th to 20th	Night	7% 3 3 8% 28% 51%	1532
	21st to end	Night	10% 3 2 9% 29% 47%	1674
August	1st to 10th	Night	10% 2 1 8% 28% 51%	1686
	11th to 20th	Night	7% 2 1 6% 32% 52%	1780
	21st to end	Night	8% 2 1 8% 31% 50%	1980
September	1st to 10th	Night	8% 2 2 7% 27% 54%	1800
	11th to 20th	Night	10% 2 2 15% 34% 37%	1800
	21st to end	Night	9% 2 1 17% 40% 31%	1981
October	1st to 10th	Night	13% 3 6% 19% 26% 33%	2160
	11th to 20th	Night	17% 5% 6% 16% 30% 27%	2160
	21st to end	Night	17% 3 3 18% 31% 28%	2376
November	1st to 10th	Night	18% 3 7% 21% 31% 21%	2298
	11th to 20th	Night	20% 3 10% 21% 26% 20%	2470
	21st to end	Night	24% 4 10% 17% 27% 18%	2470
December	1st to 10th	Night	30% 5% 8% 18% 23% 16%	2588
	11th to 20th	Night	45% 4 11% 15% 17% 7%	3276
	21st to end	Night	44% 5% 12% 21% 13% 5%	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	15% 8% 23% 32% 19% 3	270
	11th to 20th	Day	10% 8% 21% 36% 20% 5%	357
	21st to end	Day	9% 6% 21% 32% 24% 8%	374
February	1st to 10th	Day	9% 9% 23% 26% 24% 8%	364
	11th to 20th	Day	8% 10% 24% 33% 20% 5%	415
	21st to end	Day	8% 10% 26% 32% 20% 4	346
March	1st to 10th	Day	8% 14% 24% 33% 20% 1	420
	11th to 20th	Day	10% 11% 25% 27% 23% 3	420
	21st to end	Day	9% 12% 26% 32% 18% 3	462
April	1st to 10th	Day	11% 9% 24% 29% 21% 8%	420
	11th to 20th	Day	6% 10% 26% 30% 21% 7%	412
	21st to end	Day	3 8% 25% 33% 20% 12%	420
May	1st to 10th	Day	6% 7% 25% 30% 23% 9%	423
	11th to 20th	Day	3 6% 21% 35% 25% 10%	448
	21st to end	Day	5% 9% 20% 32% 23% 12%	485
June	1st to 10th	Day	3 5% 16% 28% 30% 18%	450
	11th to 20th	Day	1 3 17% 33% 26% 20%	450
	21st to end	Day	1 2 13% 29% 34% 22%	450
July	1st to 10th	Day	1 6% 36% 33% 24%	446
	11th to 20th	Day	2 4 28% 38% 28%	444
	21st to end	Day	5% 29% 38% 28%	487
August	1st to 10th	Day	2 10% 32% 35% 21%	447
	11th to 20th	Day	2 6% 26% 40% 26%	437
	21st to end	Day	3 1 4 24% 46% 23%	495
September	1st to 10th	Day	1 1 10% 26% 38% 24%	450
	11th to 20th	Day	2 2 11% 29% 41% 16%	450
	21st to end	Day	1 3 10% 27% 40% 19%	450
October	1st to 10th	Day	2 4 15% 36% 33% 11%	450
	11th to 20th	Day	3 4 17% 30% 35% 11%	450
	21st to end	Day	4 4 13% 29% 38% 12%	495
November	1st to 10th	Day	5% 5% 15% 30% 37% 9%	375
	11th to 20th	Day	6% 4 13% 35% 33% 8%	270
	21st to end	Day	5% 4 16% 38% 31% 6%	270
December	1st to 10th	Day	9% 6% 17% 37% 25% 6%	212
	11th to 20th	Day	9% 5% 23% 29% 24% 11%	180
	21st to end	Day	14% 12% 18% 32% 20% 4	198
January	1st to 10th	Night	10% 5% 17% 41% 23% 4	760
	11th to 20th	Night	8% 3 15% 47% 24% 3	744
	21st to end	Night	11% 3 16% 44% 23% 3	792
February	1st to 10th	Night	10% 4 13% 41% 28% 4	720
	11th to 20th	Night	8% 3 17% 44% 24% 4	704
	21st to end	Night	10% 5% 17% 48% 18% 2	592
March	1st to 10th	Night	10% 4 18% 46% 21% 2	720
	11th to 20th	Night	7% 5% 17% 38% 28% 5%	720
	21st to end	Night	8% 4 20% 38% 28% 2	792
April	1st to 10th	Night	6% 4 21% 40% 26% 2	720
	11th to 20th	Night	5% 5% 22% 34% 29% 5%	711
	21st to end	Night	4 4 24% 32% 28% 8%	720
May	1st to 10th	Night	3 2 19% 39% 32% 5%	720
	11th to 20th	Night	4 3 17% 36% 34% 6%	595
	21st to end	Night	3 3 17% 36% 35% 6%	389
June	1st to 10th	Night	2 3 10% 39% 41% 4	360
	11th to 20th	Night	1 11% 38% 44% 7%	360
	21st to end	Night	1 1 6% 35% 50% 8%	360
July	1st to 10th	Night	1 2 24% 63% 10%	350
	11th to 20th	Night	1 1 10% 65% 23%	488
	21st to end	Night	1 1 1 12% 60% 25%	591
August	1st to 10th	Night	1 3 23% 56% 17%	621
	11th to 20th	Night	2 22% 61% 15%	712
	21st to end	Night	1 1 19% 63% 16%	792
September	1st to 10th	Night	1 1 2 24% 58% 14%	720
	11th to 20th	Night	2 1 5% 35% 45% 12%	720
	21st to end	Night	1 1 8% 27% 52% 11%	720
October	1st to 10th	Night	4 1 8% 37% 43% 6%	720
	11th to 20th	Night	3 3 8% 37% 42% 6%	720
	21st to end	Night	5% 2 8% 38% 38% 10%	792
November	1st to 10th	Night	4 3 11% 40% 38% 4	740
	11th to 20th	Night	4 2 12% 46% 31% 4	760
	21st to end	Night	4 3 15% 46% 28% 4	760
December	1st to 10th	Night	11% 3 15% 44% 25% 3	760
	11th to 20th	Night	13% 3 14% 47% 22% 2	760
	21st to end	Night	11% 4 20% 44% 19% 2	836

Page generated at 2024-01-13 16:28:31. Version ac07

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