Rancho Caņada del Oro
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Rancho Caņada del Oro clear sky chart from 2005-11-06 to 2024-04-25.

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	8% 5% 2 4 4 3 4 4 4 7% 56%	83556
	Night	9% 6% 3 5% 5% 3 4 4 5% 7% 49%	85654
Transparency	Day	29% 5% 9% 20% 22% 15%	83276
	Night	34% 6% 10% 18% 19% 13%	85457
Seeing	Day	8% 10% 22% 32% 22% 7%	14674
	Night	9% 5% 14% 33% 31% 8%	24199

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	14% 9% 3 6% 5% 3 4 4 5% 6% 41%	2703
	11th to 20th	Day	15% 7% 4 7% 6% 4 5% 5% 5% 7% 35%	2860
	21st to end	Day	20% 8% 3 7% 6% 3 5% 5% 5% 7% 31%	3146
February	1st to 10th	Day	15% 7% 2 5% 3 3 4 4 4 6% 47%	1710
	11th to 20th	Day	13% 6% 3 4 4 3 4 5% 6% 7% 45%	1784
	21st to end	Day	15% 6% 2 4 5% 2 4 4 5% 5% 47%	1570
March	1st to 10th	Day	12% 9% 4 7% 8% 5% 8% 6% 5% 7% 28%	3349
	11th to 20th	Day	9% 5% 2 4 4 3 4 4 5% 8% 53%	3490
	21st to end	Day	12% 8% 3 7% 7% 4 5% 6% 6% 7% 33%	3908
April	1st to 10th	Day	12% 6% 2 5% 5% 3 4 4 5% 8% 48%	2280
	11th to 20th	Day	9% 5% 2 4 4 2 3 4 6% 8% 54%	2249
	21st to end	Day	6% 4 2 3 4 2 4 4 5% 9% 58%	2210
May	1st to 10th	Day	4 6% 3 4 3 2 3 4 5% 8% 60%	2175
	11th to 20th	Day	5% 4 1 4 3 2 3 4 3 8% 64%	2357
	21st to end	Day	3 6% 3 5% 4 3 4 3 5% 8% 57%	2723
June	1st to 10th	Day	4 4 2 4 3 2 2 4 4 8% 63%	2520
	11th to 20th	Day	2 3 1 2 2 2 3 3 3 7% 73%	2520
	21st to end	Day	1 2 1 3 2 2 3 2 2 6% 75%	2520
July	1st to 10th	Day	2 1 3 2 2 2 2 3 5% 76%	2520
	11th to 20th	Day	1 2 1 2 2 1 2 3 4 7% 74%	2358
	21st to end	Day	1 1 1 2 2 2 2 3 4 6% 76%	2546
August	1st to 10th	Day	1 3 1 4 3 2 3 3 4 6% 69%	2328
	11th to 20th	Day	2 1 2 3 1 2 2 4 7% 76%	2152
	21st to end	Day	2 2 3 3 2 2 2 4 7% 74%	2376
September	1st to 10th	Day	2 2 1 2 2 1 1 2 2 5% 80%	2160
	11th to 20th	Day	1 3 1 4 3 2 3 4 4 8% 66%	2160
	21st to end	Day	3 2 1 3 2 1 2 2 3 5% 77%	1925
October	1st to 10th	Day	3 3 2 2 3 2 2 4 4 6% 69%	1800
	11th to 20th	Day	4 3 1 3 3 2 3 4 4 7% 67%	1800
	21st to end	Day	5% 4 2 3 3 2 4 4 4 6% 63%	1980
November	1st to 10th	Day	8% 4 2 4 4 3 4 4 5% 7% 55%	1814
	11th to 20th	Day	8% 4 2 5% 5% 3 4 4 4 7% 54%	1710
	21st to end	Day	10% 4 2 4 3 2 3 4 4 7% 56%	1611
December	1st to 10th	Day	11% 6% 2 4 5% 4 5% 4 5% 6% 47%	1520
	11th to 20th	Day	26% 8% 3 6% 5% 3 3 4 5% 6% 32%	1928
	21st to end	Day	15% 9% 3 6% 7% 4 5% 5% 5% 7% 34%	2794
January	1st to 10th	Night	11% 10% 3 7% 4 3 4 4 5% 6% 44%	4242
	11th to 20th	Night	17% 8% 3 8% 6% 4 5% 4 5% 6% 33%	4110
	21st to end	Night	19% 11% 4 6% 5% 3 5% 4 5% 6% 32%	4521
February	1st to 10th	Night	13% 7% 2 5% 4 2 4 4 4 6% 49%	2470
	11th to 20th	Night	12% 5% 3 5% 4 3 4 5% 6% 7% 46%	2283
	21st to end	Night	12% 7% 2 5% 4 1 2 4 4 7% 50%	1884
March	1st to 10th	Night	15% 12% 5% 8% 7% 4 4 4 5% 5% 31%	3520
	11th to 20th	Night	10% 5% 2 6% 5% 3 3 3 3 9% 50%	3490
	21st to end	Night	13% 12% 4 7% 8% 4 5% 4 4 6% 33%	3743
April	1st to 10th	Night	10% 6% 3 5% 5% 3 5% 5% 6% 7% 47%	1900
	11th to 20th	Night	8% 6% 2 6% 5% 2 4 3 4 7% 53%	1879
	21st to end	Night	5% 4 2 4 3 2 4 4 5% 10% 56%	1850
May	1st to 10th	Night	3 5% 2 5% 4 3 4 4 5% 9% 55%	1782
	11th to 20th	Night	3 3 1 6% 4 3 5% 5% 5% 10% 55%	1534
	21st to end	Night	3 7% 3 4 5% 2 4 4 5% 10% 52%	1552
June	1st to 10th	Night	3 3 2 5% 5% 2 4 3 5% 9% 60%	1440
	11th to 20th	Night	1 3 2 4 5% 2 4 5% 4 8% 63%	1440
	21st to end	Night	1 3 2 4 4 3 3 4 4 7% 66%	1440
July	1st to 10th	Night	3 1 6% 4 2 4 4 4 9% 64%	1440
	11th to 20th	Night	1 1 1 5% 5% 2 4 4 4 8% 64%	1597
	21st to end	Night	1 3 2 5% 6% 3 5% 4 6% 12% 51%	1773
August	1st to 10th	Night	1 5% 2 7% 6% 3 5% 4 6% 10% 50%	1611
	11th to 20th	Night	1 3 2 5% 5% 2 4 5% 5% 8% 60%	1750
	21st to end	Night	1 2 2 5% 5% 4 4 3 5% 8% 61%	1980
September	1st to 10th	Night	1 3 1 4 2 2 3 4 4 7% 71%	1800
	11th to 20th	Night	2 4 2 6% 4 3 3 4 4 8% 60%	1800
	21st to end	Night	2 4 1 3 2 2 2 3 4 6% 72%	2032
October	1st to 10th	Night	4 3 1 3 3 3 3 3 3 7% 66%	2160
	11th to 20th	Night	4 4 2 4 4 3 3 3 5% 8% 60%	2160
	21st to end	Night	5% 4 2 4 4 2 3 3 3 7% 64%	2376
November	1st to 10th	Night	6% 4 2 5% 4 2 3 4 4 7% 59%	2262
	11th to 20th	Night	7% 5% 2 4 4 2 4 5% 5% 9% 53%	2470
	21st to end	Night	6% 4 2 5% 5% 2 4 4 4 6% 58%	2565
December	1st to 10th	Night	13% 6% 3 5% 4 3 4 4 4 5% 50%	2660
	11th to 20th	Night	25% 8% 3 5% 4 2 4 4 5% 6% 33%	3276
	21st to end	Night	16% 9% 3 7% 6% 4 5% 5% 5% 6% 33%	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	40% 7% 11% 29% 9% 3	2703
	11th to 20th	Day	47% 7% 12% 15% 11% 8%	2860
	21st to end	Day	50% 7% 8% 17% 14% 5%	3146
February	1st to 10th	Day	38% 5% 7% 21% 18% 11%	1710
	11th to 20th	Day	38% 5% 10% 18% 21% 8%	1793
	21st to end	Day	39% 5% 8% 23% 18% 7%	1570
March	1st to 10th	Day	52% 9% 9% 13% 14% 3	3349
	11th to 20th	Day	29% 5% 12% 30% 13% 11%	3490
	21st to end	Day	44% 9% 15% 19% 10% 3	3908
April	1st to 10th	Day	36% 6% 12% 22% 20% 5%	2280
	11th to 20th	Day	30% 6% 13% 25% 19% 7%	2252
	21st to end	Day	26% 6% 13% 29% 22% 5%	2210
May	1st to 10th	Day	24% 5% 12% 25% 29% 6%	2175
	11th to 20th	Day	22% 4 9% 30% 26% 8%	2360
	21st to end	Day	31% 5% 14% 25% 22% 4	2724
June	1st to 10th	Day	24% 5% 11% 26% 26% 8%	2520
	11th to 20th	Day	15% 4 10% 23% 32% 16%	2520
	21st to end	Day	17% 3 5% 14% 32% 29%	2520
July	1st to 10th	Day	15% 3 5% 11% 24% 43%	2451
	11th to 20th	Day	15% 3 7% 14% 22% 39%	2288
	21st to end	Day	13% 2 5% 12% 31% 37%	2405
August	1st to 10th	Day	21% 2 4 12% 30% 31%	2312
	11th to 20th	Day	13% 2 5% 14% 30% 36%	2152
	21st to end	Day	17% 2 5% 14% 29% 34%	2376
September	1st to 10th	Day	12% 1 3 10% 30% 43%	2160
	11th to 20th	Day	19% 3 7% 21% 32% 17%	2160
	21st to end	Day	13% 2 6% 22% 35% 22%	1925
October	1st to 10th	Day	17% 4 8% 18% 28% 27%	1800
	11th to 20th	Day	20% 4 9% 19% 22% 26%	1800
	21st to end	Day	23% 4 8% 19% 22% 22%	1980
November	1st to 10th	Day	27% 5% 8% 22% 25% 13%	1814
	11th to 20th	Day	29% 5% 10% 22% 25% 9%	1710
	21st to end	Day	29% 3 10% 17% 30% 11%	1611
December	1st to 10th	Day	36% 5% 12% 18% 17% 12%	1520
	11th to 20th	Day	54% 4 8% 15% 14% 6%	1928
	21st to end	Day	45% 6% 12% 22% 12% 4	2794
January	1st to 10th	Night	35% 8% 16% 25% 12% 4	4242
	11th to 20th	Night	46% 8% 13% 15% 10% 8%	4110
	21st to end	Night	48% 8% 11% 15% 11% 6%	4521
February	1st to 10th	Night	37% 3 8% 19% 20% 12%	2470
	11th to 20th	Night	36% 5% 11% 18% 22% 8%	2285
	21st to end	Night	32% 4 10% 29% 18% 6%	1884
March	1st to 10th	Night	49% 11% 11% 12% 13% 3	3520
	11th to 20th	Night	33% 6% 9% 23% 19% 11%	3490
	21st to end	Night	45% 9% 12% 20% 11% 4	3743
April	1st to 10th	Night	34% 7% 14% 21% 19% 6%	1900
	11th to 20th	Night	31% 5% 12% 27% 17% 7%	1879
	21st to end	Night	24% 8% 13% 27% 22% 6%	1850
May	1st to 10th	Night	28% 6% 10% 21% 23% 11%	1782
	11th to 20th	Night	30% 7% 13% 20% 24% 7%	1535
	21st to end	Night	33% 6% 14% 21% 22% 3	1552
June	1st to 10th	Night	25% 8% 12% 24% 22% 10%	1440
	11th to 20th	Night	23% 5% 8% 16% 29% 19%	1440
	21st to end	Night	27% 3 4 15% 24% 27%	1440
July	1st to 10th	Night	24% 4 5% 10% 20% 36%	1400
	11th to 20th	Night	23% 5% 8% 12% 19% 33%	1545
	21st to end	Night	33% 2 10% 12% 18% 24%	1674
August	1st to 10th	Night	36% 3 8% 13% 18% 22%	1602
	11th to 20th	Night	26% 2 6% 11% 23% 31%	1750
	21st to end	Night	29% 3 5% 11% 25% 27%	1980
September	1st to 10th	Night	16% 4 5% 10% 24% 41%	1800
	11th to 20th	Night	26% 4 6% 18% 29% 18%	1800
	21st to end	Night	17% 3 6% 16% 36% 22%	2032
October	1st to 10th	Night	22% 4 9% 15% 23% 27%	2160
	11th to 20th	Night	25% 3 7% 20% 22% 23%	2160
	21st to end	Night	24% 3 6% 20% 23% 24%	2376
November	1st to 10th	Night	26% 4 8% 23% 22% 16%	2262
	11th to 20th	Night	28% 4 10% 21% 27% 9%	2470
	21st to end	Night	28% 4 9% 19% 24% 15%	2565
December	1st to 10th	Night	36% 4 9% 19% 18% 13%	2660
	11th to 20th	Night	52% 4 9% 15% 16% 4	3276
	21st to end	Night	45% 9% 12% 17% 12% 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	26% 16% 19% 24% 13% 3	279
	11th to 20th	Day	14% 11% 23% 31% 16% 4	370
	21st to end	Day	15% 11% 23% 26% 22% 3	407
February	1st to 10th	Day	16% 18% 24% 21% 17% 6%	370
	11th to 20th	Day	15% 17% 27% 26% 13% 2	423
	21st to end	Day	15% 16% 27% 27% 13% 2	382
March	1st to 10th	Day	18% 19% 29% 23% 9% 1	460
	11th to 20th	Day	17% 17% 23% 23% 15% 4	460
	21st to end	Day	15% 18% 32% 23% 11% 1	506
April	1st to 10th	Day	14% 14% 30% 26% 14% 2	460
	11th to 20th	Day	12% 18% 28% 25% 14% 4	452
	21st to end	Day	5% 16% 29% 28% 14% 7%	437
May	1st to 10th	Day	6% 16% 32% 29% 13% 4	423
	11th to 20th	Day	9% 12% 30% 30% 15% 5%	448
	21st to end	Day	6% 12% 27% 33% 17% 6%	485
June	1st to 10th	Day	5% 9% 28% 30% 19% 9%	450
	11th to 20th	Day	2 8% 28% 40% 17% 5%	450
	21st to end	Day	1 4 22% 40% 24% 9%	450
July	1st to 10th	Day	1 1 17% 42% 32% 7%	446
	11th to 20th	Day	1 10% 43% 35% 11%	444
	21st to end	Day	10% 43% 33% 15%	487
August	1st to 10th	Day	2 1 17% 41% 31% 8%	447
	11th to 20th	Day	1 14% 42% 28% 14%	437
	21st to end	Day	1 1 12% 40% 36% 10%	495
September	1st to 10th	Day	1 4 11% 40% 31% 12%	450
	11th to 20th	Day	2 5% 24% 38% 22% 10%	450
	21st to end	Day	3 6% 18% 36% 29% 8%	450
October	1st to 10th	Day	2 9% 24% 29% 27% 9%	450
	11th to 20th	Day	5% 8% 19% 30% 27% 10%	450
	21st to end	Day	7% 6% 21% 33% 25% 8%	495
November	1st to 10th	Day	8% 11% 17% 26% 30% 9%	410
	11th to 20th	Day	7% 7% 18% 30% 28% 10%	270
	21st to end	Day	9% 6% 20% 34% 25% 5%	223
December	1st to 10th	Day	11% 13% 20% 27% 21% 7%	180
	11th to 20th	Day	14% 15% 18% 25% 19% 8%	180
	21st to end	Day	15% 17% 20% 26% 16% 6%	198
January	1st to 10th	Night	17% 6% 16% 32% 23% 6%	760
	11th to 20th	Night	14% 6% 14% 35% 23% 9%	760
	21st to end	Night	18% 5% 14% 34% 24% 5%	836
February	1st to 10th	Night	16% 9% 14% 33% 23% 6%	760
	11th to 20th	Night	15% 8% 18% 34% 20% 6%	744
	21st to end	Night	15% 7% 20% 36% 19% 3	628
March	1st to 10th	Night	15% 10% 20% 31% 20% 4	760
	11th to 20th	Night	16% 9% 18% 29% 24% 5%	760
	21st to end	Night	13% 9% 23% 33% 19% 3	836
April	1st to 10th	Night	11% 7% 21% 34% 23% 3	760
	11th to 20th	Night	10% 10% 20% 34% 21% 5%	751
	21st to end	Night	6% 7% 25% 33% 23% 7%	740
May	1st to 10th	Night	5% 4 23% 36% 27% 5%	702
	11th to 20th	Night	5% 3 13% 36% 36% 7%	472
	21st to end	Night	4 5% 17% 39% 31% 5%	389
June	1st to 10th	Night	4 4 13% 39% 34% 6%	360
	11th to 20th	Night	1 3 14% 45% 35% 3	360
	21st to end	Night	1 1 9% 36% 47% 6%	360
July	1st to 10th	Night	1 5% 32% 56% 6%	350
	11th to 20th	Night	1 1 25% 56% 17%	501
	21st to end	Night	1 5% 25% 53% 16%	591
August	1st to 10th	Night	3 7% 33% 48% 8%	537
	11th to 20th	Night	1 7% 35% 46% 10%	682
	21st to end	Night	1 4 31% 52% 12%	792
September	1st to 10th	Night	2 1 6% 31% 47% 13%	720
	11th to 20th	Night	3 2 9% 35% 42% 10%	720
	21st to end	Night	3 2 11% 31% 41% 12%	720
October	1st to 10th	Night	4 3 11% 35% 35% 12%	720
	11th to 20th	Night	6% 3 12% 31% 36% 11%	720
	21st to end	Night	6% 3 11% 33% 29% 17%	792
November	1st to 10th	Night	7% 4 16% 31% 32% 11%	740
	11th to 20th	Night	9% 3 14% 36% 31% 7%	760
	21st to end	Night	8% 4 16% 37% 27% 8%	760
December	1st to 10th	Night	14% 7% 15% 33% 25% 6%	760
	11th to 20th	Night	18% 7% 17% 33% 21% 5%	760
	21st to end	Night	16% 9% 21% 32% 18% 4	836

Page generated at 2024-04-22 06:25:45. Version ac07

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