Loup Canal
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Loup Canal clear sky chart from 2005-11-06 to 2024-01-14.

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	11% 6% 3 5% 5% 3 4 4 5% 7% 46%	74906
	Night	10% 6% 3 5% 4 3 4 4 5% 7% 49%	74797
Transparency	Day	37% 5% 14% 26% 15% 2	74620
	Night	34% 5% 13% 27% 17% 3	74603
Seeing	Day	14% 9% 30% 30% 14% 3	14640
	Night	12% 9% 34% 34% 10%	24673

By Month

Percentage Cloud Cover SE (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	9% 9% 3 7% 5% 3 4 6% 4 7% 43%	1555
	11th to 20th	Day	9% 10% 4 8% 5% 2 4 5% 5% 5% 43%	1647
	21st to end	Day	9% 9% 4 11% 8% 3 4 5% 3 8% 35%	1782
February	1st to 10th	Day	9% 11% 5% 8% 7% 3 5% 3 4 7% 38%	1620
	11th to 20th	Day	9% 9% 3 6% 6% 3 5% 4 5% 8% 42%	1676
	21st to end	Day	9% 10% 3 5% 5% 3 4 5% 5% 6% 43%	1480
March	1st to 10th	Day	11% 6% 3 5% 5% 2 4 4 4 6% 48%	1883
	11th to 20th	Day	15% 8% 3 5% 5% 2 4 4 5% 7% 42%	1980
	21st to end	Day	16% 12% 4 8% 6% 2 5% 5% 4 6% 31%	2178
April	1st to 10th	Day	14% 8% 3 5% 5% 3 3 4 4 7% 44%	2006
	11th to 20th	Day	16% 8% 4 6% 5% 3 4 4 4 6% 41%	2303
	21st to end	Day	19% 8% 3 5% 4 2 4 4 5% 6% 40%	2340
May	1st to 10th	Day	15% 7% 3 6% 5% 3 5% 5% 5% 7% 40%	2340
	11th to 20th	Day	16% 7% 2 5% 5% 3 4 5% 5% 7% 40%	2302
	21st to end	Day	15% 6% 3 6% 6% 3 4 6% 6% 7% 37%	2531
June	1st to 10th	Day	7% 4 2 5% 5% 3 5% 5% 6% 9% 50%	2371
	11th to 20th	Day	10% 5% 2 3 5% 2 4 5% 6% 9% 49%	2666
	21st to end	Day	7% 4 1 4 4 3 4 4 7% 10% 53%	2520
July	1st to 10th	Day	9% 3 2 3 5% 3 4 5% 6% 10% 49%	2520
	11th to 20th	Day	6% 3 2 3 3 2 4 5% 6% 9% 56%	2401
	21st to end	Day	6% 4 1 4 5% 3 5% 6% 7% 11% 49%	2546
August	1st to 10th	Day	7% 6% 3 6% 6% 4 6% 5% 6% 9% 41%	2328
	11th to 20th	Day	8% 4 2 4 4 3 4 4 6% 8% 52%	2301
	21st to end	Day	9% 5% 2 4 4 3 5% 4 5% 7% 54%	2574
September	1st to 10th	Day	13% 5% 2 4 4 2 4 3 4 6% 53%	2020
	11th to 20th	Day	10% 4 2 3 4 2 3 4 4 7% 57%	1980
	21st to end	Day	11% 3 2 3 3 2 3 3 4 8% 58%	1980
October	1st to 10th	Day	15% 7% 2 4 4 2 3 3 3 5% 51%	1903
	11th to 20th	Day	11% 4 2 3 3 2 4 3 5% 5% 59%	1800
	21st to end	Day	15% 6% 3 4 4 3 3 3 5% 5% 50%	1908
November	1st to 10th	Day	9% 4 2 4 4 2 3 4 5% 8% 55%	1673
	11th to 20th	Day	9% 5% 3 6% 6% 3 3 4 5% 7% 51%	1710
	21st to end	Day	12% 8% 3 6% 4 2 4 3 4 8% 47%	1601
December	1st to 10th	Day	8% 7% 3 6% 6% 3 4 4 5% 6% 48%	1520
	11th to 20th	Day	7% 7% 4 7% 5% 4 5% 6% 6% 8% 42%	1918
	21st to end	Day	14% 9% 4 10% 6% 3 5% 5% 5% 6% 33%	3043
January	1st to 10th	Night	8% 8% 3 7% 6% 3 5% 5% 5% 7% 43%	2595
	11th to 20th	Night	7% 10% 4 8% 6% 3 4 5% 5% 6% 43%	2392
	21st to end	Night	8% 9% 4 7% 6% 3 4 4 6% 8% 41%	2574
February	1st to 10th	Night	11% 10% 3 6% 7% 3 4 5% 4 5% 41%	2340
	11th to 20th	Night	8% 7% 4 6% 6% 3 5% 6% 6% 8% 43%	2185
	21st to end	Night	8% 6% 3 6% 5% 3 4 4 5% 7% 48%	1776
March	1st to 10th	Night	10% 7% 4 5% 4 3 4 4 5% 6% 49%	2076
	11th to 20th	Night	13% 8% 3 5% 3 2 4 3 5% 6% 47%	1980
	21st to end	Night	16% 8% 3 6% 6% 3 5% 5% 6% 8% 35%	2178
April	1st to 10th	Night	13% 6% 2 6% 5% 2 4 5% 5% 6% 45%	1952
	11th to 20th	Night	12% 7% 3 5% 5% 3 5% 4 5% 7% 44%	1606
	21st to end	Night	15% 5% 3 4 5% 2 5% 4 5% 6% 46%	1620
May	1st to 10th	Night	13% 6% 3 4 5% 3 4 5% 6% 7% 44%	1620
	11th to 20th	Night	12% 5% 3 5% 5% 3 3 5% 5% 8% 48%	1593
	21st to end	Night	15% 6% 3 5% 5% 3 4 4 5% 10% 40%	1745
June	1st to 10th	Night	5% 3 2 4 4 3 4 5% 6% 9% 55%	1576
	11th to 20th	Night	6% 5% 2 5% 5% 3 4 4 5% 9% 54%	1273
	21st to end	Night	4 3 1 3 4 3 5% 4 6% 9% 58%	1440
July	1st to 10th	Night	7% 4 2 4 4 2 4 4 5% 8% 56%	1440
	11th to 20th	Night	3 2 1 2 3 3 5% 5% 7% 9% 59%	1556
	21st to end	Night	4 3 2 4 3 2 4 5% 6% 11% 56%	1772
August	1st to 10th	Night	5% 4 2 4 6% 3 4 5% 6% 10% 50%	1611
	11th to 20th	Night	6% 3 2 5% 3 3 5% 3 6% 8% 58%	1600
	21st to end	Night	7% 3 2 5% 4 2 4 3 5% 8% 59%	1782
September	1st to 10th	Night	9% 3 1 4 3 2 4 3 4 5% 61%	1934
	11th to 20th	Night	9% 3 1 3 4 2 3 3 5% 7% 60%	1980
	21st to end	Night	9% 3 1 3 4 2 3 4 4 6% 60%	1980
October	1st to 10th	Night	15% 5% 2 4 4 2 3 4 5% 7% 50%	2038
	11th to 20th	Night	12% 5% 2 3 3 2 2 3 4 6% 59%	2160
	21st to end	Night	14% 4 2 3 3 2 3 4 4 7% 54%	2445
November	1st to 10th	Night	6% 4 2 3 3 2 4 3 5% 6% 60%	2405
	11th to 20th	Night	10% 6% 2 4 5% 2 4 3 4 7% 53%	2470
	21st to end	Night	10% 7% 3 4 3 2 4 3 4 7% 54%	2574
December	1st to 10th	Night	7% 7% 3 5% 5% 3 4 4 5% 7% 50%	2660
	11th to 20th	Night	8% 6% 3 6% 4 3 4 4 5% 8% 50%	3279
	21st to end	Night	15% 11% 3 10% 4 3 3 4 4 5% 36%	4590

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	42% 4 17% 23% 13% 2	1556
	11th to 20th	Day	44% 5% 13% 24% 12% 2	1647
	21st to end	Day	48% 6% 15% 20% 10% 1	1782
February	1st to 10th	Day	47% 5% 14% 22% 11% 2	1620
	11th to 20th	Day	42% 5% 12% 23% 15% 3	1685
	21st to end	Day	40% 6% 13% 24% 14% 3	1480
March	1st to 10th	Day	37% 5% 13% 28% 15% 3	1883
	11th to 20th	Day	42% 5% 12% 24% 15% 2	1980
	21st to end	Day	53% 5% 14% 19% 7% 1	2178
April	1st to 10th	Day	41% 5% 13% 26% 14% 1	2006
	11th to 20th	Day	44% 4 12% 23% 13% 3	2303
	21st to end	Day	45% 5% 12% 24% 14%	2340
May	1st to 10th	Day	43% 6% 14% 22% 14% 1	2340
	11th to 20th	Day	43% 6% 16% 23% 13%	2306
	21st to end	Day	45% 7% 15% 20% 11% 2	2531
June	1st to 10th	Day	29% 7% 18% 32% 13% 2	2371
	11th to 20th	Day	31% 7% 15% 28% 17% 3	2666
	21st to end	Day	28% 6% 16% 31% 15% 4	2520
July	1st to 10th	Day	29% 7% 16% 30% 17% 2	2451
	11th to 20th	Day	25% 7% 15% 29% 20% 5%	2328
	21st to end	Day	27% 7% 17% 30% 16% 2	2405
August	1st to 10th	Day	37% 8% 16% 27% 11% 2	2314
	11th to 20th	Day	29% 6% 15% 33% 15% 1	2301
	21st to end	Day	30% 5% 12% 27% 21% 5%	2574
September	1st to 10th	Day	33% 5% 11% 26% 20% 6%	2020
	11th to 20th	Day	28% 5% 13% 33% 19% 2	1980
	21st to end	Day	27% 4 10% 33% 26% 1	1980
October	1st to 10th	Day	36% 4 10% 25% 23% 2	1903
	11th to 20th	Day	29% 3 10% 29% 21% 7%	1800
	21st to end	Day	38% 3 12% 22% 20% 4	1908
November	1st to 10th	Day	29% 4 14% 29% 21% 3	1673
	11th to 20th	Day	33% 4 12% 27% 22% 2	1710
	21st to end	Day	38% 4 12% 28% 16% 2	1601
December	1st to 10th	Day	37% 3 16% 29% 13% 3	1520
	11th to 20th	Day	39% 5% 16% 30% 9%	1915
	21st to end	Day	51% 6% 11% 22% 9% 1	3043
January	1st to 10th	Night	39% 5% 14% 26% 15% 1	2595
	11th to 20th	Night	42% 5% 13% 27% 12% 1	2392
	21st to end	Night	42% 6% 15% 24% 12% 1	2574
February	1st to 10th	Night	46% 5% 13% 21% 14% 2	2340
	11th to 20th	Night	39% 6% 14% 24% 14% 3	2186
	21st to end	Night	35% 4 12% 26% 18% 4	1776
March	1st to 10th	Night	36% 5% 12% 28% 17% 3	2076
	11th to 20th	Night	38% 5% 11% 25% 18% 3	1980
	21st to end	Night	47% 5% 15% 22% 9% 1	2178
April	1st to 10th	Night	38% 5% 12% 26% 17% 1	1952
	11th to 20th	Night	39% 6% 12% 25% 16% 3	1606
	21st to end	Night	38% 6% 11% 25% 18% 1	1620
May	1st to 10th	Night	39% 5% 14% 24% 17% 1	1620
	11th to 20th	Night	37% 6% 17% 26% 15%	1594
	21st to end	Night	40% 6% 17% 20% 15% 2	1746
June	1st to 10th	Night	26% 6% 18% 33% 15% 2	1576
	11th to 20th	Night	28% 5% 15% 28% 19% 4	1273
	21st to end	Night	24% 4 17% 31% 20% 4	1440
July	1st to 10th	Night	27% 5% 16% 29% 20% 4	1400
	11th to 20th	Night	21% 7% 17% 27% 24% 5%	1506
	21st to end	Night	21% 6% 18% 35% 18% 3	1673
August	1st to 10th	Night	28% 8% 18% 30% 13% 2	1601
	11th to 20th	Night	24% 5% 15% 33% 20% 3	1600
	21st to end	Night	25% 6% 12% 25% 24% 8%	1782
September	1st to 10th	Night	26% 4 10% 30% 21% 9%	1934
	11th to 20th	Night	24% 5% 10% 34% 23% 4	1980
	21st to end	Night	25% 5% 8% 31% 27% 4	1980
October	1st to 10th	Night	35% 5% 10% 24% 25% 2	2038
	11th to 20th	Night	29% 3 8% 27% 26% 6%	2160
	21st to end	Night	32% 4 13% 25% 23% 4	2445
November	1st to 10th	Night	24% 4 13% 29% 25% 5%	2405
	11th to 20th	Night	32% 4 11% 29% 20% 4	2470
	21st to end	Night	33% 3 13% 29% 20% 3	2574
December	1st to 10th	Night	35% 5% 14% 30% 15% 2	2660
	11th to 20th	Night	33% 4 14% 36% 12% 1	3281
	21st to end	Night	51% 6% 10% 24% 8% 1	4590

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	13% 15% 34% 26% 10% 2	270
	11th to 20th	Day	19% 15% 31% 28% 6%	249
	21st to end	Day	16% 6% 47% 23% 6%	264
February	1st to 10th	Day	13% 18% 37% 29% 3	240
	11th to 20th	Day	15% 13% 41% 21% 8% 1	240
	21st to end	Day	15% 18% 42% 21% 3 1	198
March	1st to 10th	Day	16% 14% 41% 21% 6% 1	240
	11th to 20th	Day	27% 8% 35% 23% 7% 1	240
	21st to end	Day	28% 15% 36% 16% 5%	264
April	1st to 10th	Day	19% 19% 39% 18% 5%	266
	11th to 20th	Day	20% 15% 38% 22% 6%	581
	21st to end	Day	23% 14% 30% 22% 9% 2	600
May	1st to 10th	Day	18% 11% 34% 27% 9% 1	603
	11th to 20th	Day	20% 11% 30% 22% 14% 3	625
	21st to end	Day	18% 8% 27% 32% 12% 3	679
June	1st to 10th	Day	5% 6% 25% 37% 21% 5%	630
	11th to 20th	Day	10% 5% 34% 32% 15% 3	630
	21st to end	Day	7% 7% 31% 35% 17% 2	630
July	1st to 10th	Day	10% 3 18% 34% 29% 6%	621
	11th to 20th	Day	5% 3 22% 42% 22% 5%	618
	21st to end	Day	7% 2 19% 45% 24% 3	684
August	1st to 10th	Day	7% 3 20% 41% 25% 3	626
	11th to 20th	Day	10% 5% 18% 42% 23% 4	615
	21st to end	Day	10% 3 24% 36% 23% 4	693
September	1st to 10th	Day	16% 4 25% 36% 14% 5%	310
	11th to 20th	Day	8% 5% 34% 31% 15% 6%	270
	21st to end	Day	16% 5% 33% 29% 13% 3	270
October	1st to 10th	Day	22% 7% 29% 25% 13% 4	270
	11th to 20th	Day	15% 11% 39% 23% 11% 1	270
	21st to end	Day	22% 15% 32% 22% 8% 1	297
November	1st to 10th	Day	12% 16% 39% 21% 9% 3	270
	11th to 20th	Day	13% 14% 42% 23% 7%	270
	21st to end	Day	20% 15% 29% 23% 11% 1	270
December	1st to 10th	Day	11% 9% 45% 27% 7% 1	270
	11th to 20th	Day	14% 13% 38% 26% 9%	270
	21st to end	Day	20% 13% 39% 23% 5%	297
January	1st to 10th	Night	13% 13% 35% 31% 7% 1	950
	11th to 20th	Night	13% 11% 38% 30% 7% 1	920
	21st to end	Night	14% 8% 43% 29% 5%	990
February	1st to 10th	Night	16% 12% 39% 29% 4	900
	11th to 20th	Night	11% 11% 43% 30% 5%	791
	21st to end	Night	11% 11% 45% 26% 7%	592
March	1st to 10th	Night	14% 13% 37% 30% 5% 1	636
	11th to 20th	Night	17% 12% 36% 29% 6%	540
	21st to end	Night	19% 10% 41% 25% 6%	594
April	1st to 10th	Night	17% 13% 40% 26% 3	540
	11th to 20th	Night	15% 14% 38% 29% 4	533
	21st to end	Night	18% 10% 34% 31% 7%	540
May	1st to 10th	Night	15% 9% 37% 31% 8%	540
	11th to 20th	Night	14% 9% 33% 33% 11%	531
	21st to end	Night	16% 6% 32% 33% 13% 1	584
June	1st to 10th	Night	7% 3 25% 50% 14% 1	540
	11th to 20th	Night	8% 6% 32% 41% 11%	540
	21st to end	Night	5% 3 30% 48% 14%	540
July	1st to 10th	Night	8% 2 20% 42% 28%	525
	11th to 20th	Night	3 1 23% 49% 23% 1	522
	21st to end	Night	5% 2 17% 55% 20%	591
August	1st to 10th	Night	6% 1 18% 49% 24% 2	537
	11th to 20th	Night	7% 2 21% 48% 22%	534
	21st to end	Night	9% 1 28% 39% 22% 2	594
September	1st to 10th	Night	11% 3 25% 41% 19% 1	540
	11th to 20th	Night	10% 3 30% 41% 15% 1	540
	21st to end	Night	10% 6% 35% 34% 15% 1	540
October	1st to 10th	Night	18% 7% 31% 31% 12% 1	598
	11th to 20th	Night	14% 12% 36% 31% 6%	720
	21st to end	Night	17% 11% 30% 33% 10% 1	861
November	1st to 10th	Night	8% 10% 36% 37% 7% 1	925
	11th to 20th	Night	12% 11% 39% 30% 7%	950
	21st to end	Night	13% 11% 36% 29% 10%	950
December	1st to 10th	Night	11% 12% 41% 30% 6%	950
	11th to 20th	Night	14% 9% 37% 32% 7%	950
	21st to end	Night	17% 12% 37% 29% 5%	1045

Page generated at 2024-01-11 12:32:00. Version ac07

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