Rimouski
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Rimouski clear sky chart from 2005-11-06 to 2024-11-03.

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	17% 10% 3 8% 6% 5% 5% 4 5% 6% 31%	101716
	Night	17% 13% 4 10% 7% 6% 5% 3 5% 5% 25%	97338
Transparency	Day	52% 7% 14% 18% 7% 1	101460
	Night	59% 7% 12% 15% 7% 1	97215
Seeing	Day	22% 11% 28% 26% 11% 2	15911
	Night	23% 12% 28% 26% 10% 1	23815

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	13% 18% 6% 16% 14% 14% 5% 3 3 2 6%	2207
	11th to 20th	Day	11% 12% 5% 19% 17% 9% 7% 5% 4 4 8%	2431
	21st to end	Day	6% 11% 4 12% 11% 11% 8% 5% 5% 5% 21%	2772
February	1st to 10th	Day	8% 12% 6% 10% 11% 10% 6% 5% 5% 6% 20%	1607
	11th to 20th	Day	13% 16% 5% 13% 8% 7% 6% 4 5% 4 19%	1667
	21st to end	Day	11% 12% 4 10% 8% 8% 6% 5% 5% 7% 23%	1570
March	1st to 10th	Day	14% 11% 4 9% 6% 7% 6% 4 6% 8% 26%	3116
	11th to 20th	Day	22% 19% 4 9% 5% 5% 4 3 5% 5% 19%	3480
	21st to end	Day	20% 17% 5% 11% 4 4 3 2 4 5% 26%	3832
April	1st to 10th	Day	20% 13% 5% 7% 5% 4 4 4 4 6% 27%	2315
	11th to 20th	Day	18% 11% 4 7% 4 4 3 3 6% 7% 33%	2442
	21st to end	Day	22% 11% 3 7% 3 4 3 3 5% 5% 34%	2470
May	1st to 10th	Day	16% 10% 3 8% 5% 4 5% 4 5% 6% 35%	4106
	11th to 20th	Day	19% 9% 3 6% 5% 4 4 4 6% 7% 34%	4591
	21st to end	Day	19% 8% 3 7% 5% 4 4 4 5% 8% 34%	5185
June	1st to 10th	Day	20% 8% 3 6% 5% 4 5% 4 6% 6% 32%	2850
	11th to 20th	Day	19% 7% 2 5% 5% 4 4 4 6% 8% 36%	2850
	21st to end	Day	20% 7% 3 8% 5% 4 5% 5% 5% 8% 30%	2850
July	1st to 10th	Day	16% 7% 3 7% 5% 5% 5% 4 6% 7% 36%	4760
	11th to 20th	Day	13% 6% 2 7% 5% 5% 6% 5% 7% 8% 37%	4760
	21st to end	Day	11% 5% 2 7% 5% 5% 4 4 7% 7% 43%	4847
August	1st to 10th	Day	12% 5% 2 7% 5% 4 6% 5% 8% 10% 37%	4267
	11th to 20th	Day	17% 6% 2 7% 5% 5% 5% 4 7% 7% 35%	4045
	21st to end	Day	16% 6% 2 6% 4 4 4 4 6% 7% 41%	4532
September	1st to 10th	Day	17% 6% 2 5% 3 4 4 4 5% 7% 42%	2286
	11th to 20th	Day	20% 6% 1 5% 3 3 4 2 4 5% 47%	2090
	21st to end	Day	17% 7% 2 6% 5% 4 4 3 5% 6% 40%	2090
October	1st to 10th	Day	18% 10% 2 6% 5% 4 4 4 5% 6% 36%	1995
	11th to 20th	Day	25% 11% 3 6% 5% 4 3 3 5% 6% 29%	1825
	21st to end	Day	25% 13% 2 6% 4 4 5% 3 5% 6% 28%	1881
November	1st to 10th	Day	19% 14% 5% 8% 6% 4 4 4 6% 5% 26%	1642
	11th to 20th	Day	19% 16% 6% 12% 5% 5% 3 3 4 5% 21%	1520
	21st to end	Day	20% 17% 5% 13% 6% 4 3 4 4 5% 18%	1406
December	1st to 10th	Day	16% 20% 7% 15% 11% 6% 5% 2 4 4 10%	1330
	11th to 20th	Day	17% 18% 6% 15% 10% 7% 5% 2 3 3 15%	1668
	21st to end	Day	19% 12% 5% 14% 10% 6% 4 3 4 5% 18%	2431
January	1st to 10th	Night	11% 18% 7% 19% 16% 10% 5% 3 3 3 6%	4748
	11th to 20th	Night	12% 17% 7% 13% 10% 8% 5% 4 4 4 15%	4532
	21st to end	Night	7% 13% 5% 12% 10% 8% 7% 4 4 6% 23%	4884
February	1st to 10th	Night	10% 14% 6% 13% 10% 8% 6% 4 4 4 22%	2571
	11th to 20th	Night	13% 16% 7% 12% 9% 6% 5% 3 5% 5% 20%	2394
	21st to end	Night	11% 14% 5% 11% 9% 9% 5% 4 4 5% 24%	1884
March	1st to 10th	Night	13% 13% 5% 10% 7% 6% 7% 4 5% 5% 26%	3710
	11th to 20th	Night	22% 23% 5% 9% 6% 5% 4 2 3 4 17%	3479
	21st to end	Night	23% 15% 5% 9% 4 4 3 3 4 5% 25%	3799
April	1st to 10th	Night	23% 15% 4 9% 6% 4 4 2 4 4 25%	1864
	11th to 20th	Night	21% 11% 2 7% 4 3 5% 4 6% 6% 31%	1688
	21st to end	Night	26% 10% 3 6% 3 4 4 3 4 5% 33%	1710
May	1st to 10th	Night	21% 8% 3 7% 4 4 6% 4 5% 7% 32%	2834
	11th to 20th	Night	18% 9% 3 7% 5% 4 4 4 6% 7% 32%	2339
	21st to end	Night	21% 7% 2 7% 6% 5% 5% 4 6% 7% 30%	2401
June	1st to 10th	Night	20% 9% 3 8% 5% 4 5% 4 5% 7% 30%	1330
	11th to 20th	Night	19% 8% 2 6% 4 5% 4 4 7% 8% 33%	1330
	21st to end	Night	23% 8% 4 7% 5% 5% 5% 4 5% 6% 30%	1330
July	1st to 10th	Night	16% 7% 3 7% 5% 5% 5% 4 7% 7% 33%	2210
	11th to 20th	Night	13% 7% 3 8% 5% 5% 5% 5% 8% 10% 31%	2210
	21st to end	Night	12% 6% 3 6% 4 5% 5% 5% 7% 9% 39%	2703
August	1st to 10th	Night	17% 6% 2 7% 6% 6% 5% 4 7% 8% 31%	2630
	11th to 20th	Night	14% 7% 3 9% 6% 7% 5% 5% 8% 7% 29%	2782
	21st to end	Night	19% 7% 2 6% 4 4 4 3 5% 6% 41%	3124
September	1st to 10th	Night	17% 6% 2 7% 5% 4 4 4 6% 6% 40%	1889
	11th to 20th	Night	21% 7% 3 6% 4 4 3 3 4 6% 39%	2090
	21st to end	Night	18% 7% 2 6% 5% 3 3 3 4 6% 43%	2090
October	1st to 10th	Night	20% 7% 2 6% 5% 4 5% 3 5% 5% 39%	2184
	11th to 20th	Night	26% 11% 3 7% 4 4 3 3 5% 6% 28%	2351
	21st to end	Night	22% 14% 4 8% 4 4 3 3 4 7% 27%	2717
November	1st to 10th	Night	21% 14% 4 10% 5% 4 4 3 5% 5% 26%	2481
	11th to 20th	Night	21% 17% 5% 11% 5% 4 4 3 3 4 23%	2660
	21st to end	Night	19% 18% 6% 14% 7% 4 4 3 4 4 16%	2773
December	1st to 10th	Night	20% 17% 6% 15% 10% 7% 4 2 4 3 12%	2850
	11th to 20th	Night	18% 18% 5% 14% 11% 7% 4 3 3 4 13%	3531
	21st to end	Night	17% 17% 6% 12% 9% 6% 5% 3 4 5% 17%	5236

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	82% 7% 7% 4 1	2208
	11th to 20th	Day	75% 6% 9% 6% 3	2431
	21st to end	Day	60% 9% 10% 16% 4	2772
February	1st to 10th	Day	62% 7% 11% 12% 6% 1	1607
	11th to 20th	Day	67% 5% 12% 11% 4	1675
	21st to end	Day	60% 4 12% 18% 6%	1570
March	1st to 10th	Day	55% 9% 16% 14% 4 1	3119
	11th to 20th	Day	66% 6% 11% 12% 5%	3480
	21st to end	Day	62% 3 8% 18% 6% 2	3832
April	1st to 10th	Day	58% 4 12% 16% 9% 1	2315
	11th to 20th	Day	50% 5% 14% 20% 11% 1	2442
	21st to end	Day	52% 5% 9% 20% 13% 2	2470
May	1st to 10th	Day	49% 8% 15% 19% 8% 1	4120
	11th to 20th	Day	47% 11% 13% 20% 10%	4595
	21st to end	Day	46% 7% 11% 24% 10% 1	5185
June	1st to 10th	Day	51% 7% 11% 18% 12% 1	2850
	11th to 20th	Day	46% 7% 14% 20% 12% 1	2850
	21st to end	Day	52% 8% 14% 17% 9% 1	2850
July	1st to 10th	Day	46% 6% 14% 25% 9%	4685
	11th to 20th	Day	42% 9% 22% 22% 6%	4679
	21st to end	Day	37% 9% 20% 25% 8%	4692
August	1st to 10th	Day	39% 9% 23% 23% 6%	4253
	11th to 20th	Day	46% 9% 22% 19% 4	4084
	21st to end	Day	42% 7% 20% 20% 11%	4532
September	1st to 10th	Day	41% 7% 17% 24% 10%	2286
	11th to 20th	Day	40% 5% 17% 28% 10%	2090
	21st to end	Day	44% 7% 15% 24% 10%	2090
October	1st to 10th	Day	47% 6% 16% 21% 8% 1	1995
	11th to 20th	Day	56% 6% 16% 19% 4	1825
	21st to end	Day	57% 6% 14% 16% 6%	1881
November	1st to 10th	Day	59% 7% 14% 15% 5%	1642
	11th to 20th	Day	64% 6% 13% 13% 3	1520
	21st to end	Day	67% 5% 13% 12% 3	1406
December	1st to 10th	Day	78% 5% 9% 6% 1	1330
	11th to 20th	Day	73% 5% 8% 10% 3	1668
	21st to end	Day	67% 7% 11% 11% 3	2431
January	1st to 10th	Night	81% 8% 6% 4 1	4748
	11th to 20th	Night	68% 8% 10% 11% 4	4532
	21st to end	Night	59% 9% 9% 16% 6%	4884
February	1st to 10th	Night	64% 6% 9% 12% 7% 1	2571
	11th to 20th	Night	67% 5% 11% 12% 5%	2397
	21st to end	Night	62% 5% 9% 17% 6% 1	1884
March	1st to 10th	Night	58% 9% 10% 15% 7%	3720
	11th to 20th	Night	72% 4 8% 10% 5%	3480
	21st to end	Night	61% 4 10% 17% 7% 1	3799
April	1st to 10th	Night	64% 4 7% 13% 11% 2	1864
	11th to 20th	Night	52% 6% 8% 18% 14% 1	1688
	21st to end	Night	55% 4 8% 19% 13% 1	1710
May	1st to 10th	Night	49% 8% 15% 14% 12% 1	2840
	11th to 20th	Night	47% 8% 12% 22% 10% 1	2340
	21st to end	Night	49% 10% 9% 22% 10% 1	2402
June	1st to 10th	Night	52% 7% 11% 19% 10% 2	1330
	11th to 20th	Night	48% 7% 11% 19% 13% 2	1330
	21st to end	Night	54% 7% 10% 18% 10%	1330
July	1st to 10th	Night	48% 8% 13% 26% 6%	2175
	11th to 20th	Night	44% 9% 22% 19% 5%	2168
	21st to end	Night	39% 10% 21% 19% 10%	2617
August	1st to 10th	Night	48% 8% 17% 22% 5%	2620
	11th to 20th	Night	49% 12% 21% 13% 5%	2809
	21st to end	Night	43% 8% 14% 22% 13%	3124
September	1st to 10th	Night	42% 9% 14% 25% 10% 1	1889
	11th to 20th	Night	46% 6% 17% 23% 9% 1	2090
	21st to end	Night	43% 6% 13% 25% 12% 1	2090
October	1st to 10th	Night	47% 6% 12% 23% 11% 1	2184
	11th to 20th	Night	58% 5% 14% 19% 4	2351
	21st to end	Night	58% 5% 14% 16% 5% 1	2717
November	1st to 10th	Night	59% 6% 14% 15% 5% 1	2481
	11th to 20th	Night	64% 5% 12% 14% 4	2660
	21st to end	Night	72% 5% 12% 7% 3	2773
December	1st to 10th	Night	76% 5% 10% 8% 2	2850
	11th to 20th	Night	75% 5% 8% 9% 3	3532
	21st to end	Night	68% 7% 12% 9% 5%	5236

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	21% 14% 39% 18% 6% 1	180
	11th to 20th	Day	21% 21% 29% 22% 8%	180
	21st to end	Day	15% 13% 39% 18% 14% 1	198
February	1st to 10th	Day	15% 15% 39% 23% 6% 2	267
	11th to 20th	Day	16% 17% 38% 23% 6%	368
	21st to end	Day	16% 16% 36% 21% 8% 2	382
March	1st to 10th	Day	20% 15% 30% 28% 6% 1	460
	11th to 20th	Day	24% 17% 25% 20% 13% 2	460
	21st to end	Day	24% 13% 32% 21% 8% 2	506
April	1st to 10th	Day	25% 14% 27% 25% 8% 1	460
	11th to 20th	Day	22% 12% 29% 27% 10% 2	452
	21st to end	Day	24% 12% 32% 22% 7% 3	460
May	1st to 10th	Day	25% 11% 28% 24% 9% 2	463
	11th to 20th	Day	23% 8% 27% 27% 13% 2	622
	21st to end	Day	25% 10% 31% 24% 8% 2	735
June	1st to 10th	Day	23% 8% 29% 28% 11% 2	680
	11th to 20th	Day	22% 7% 27% 28% 15% 2	680
	21st to end	Day	21% 7% 24% 33% 13% 2	680
July	1st to 10th	Day	20% 4 29% 34% 11% 2	670
	11th to 20th	Day	14% 6% 26% 36% 16% 2	668
	21st to end	Day	14% 5% 26% 36% 16% 2	552
August	1st to 10th	Day	14% 8% 25% 34% 16% 3	486
	11th to 20th	Day	18% 5% 20% 37% 18% 3	479
	21st to end	Day	17% 8% 23% 30% 16% 5%	539
September	1st to 10th	Day	20% 8% 26% 28% 15% 3	490
	11th to 20th	Day	21% 9% 28% 24% 15% 2	490
	21st to end	Day	19% 10% 29% 26% 11% 5%	490
October	1st to 10th	Day	21% 10% 32% 23% 12% 3	440
	11th to 20th	Day	32% 11% 23% 22% 10% 2	390
	21st to end	Day	33% 16% 25% 18% 7% 1	429
November	1st to 10th	Day	27% 18% 29% 21% 4	371
	11th to 20th	Day	29% 15% 28% 20% 8% 1	370
	21st to end	Day	25% 22% 30% 20% 4	256
December	1st to 10th	Day	25% 12% 31% 21% 9% 2	180
	11th to 20th	Day	25% 22% 34% 13% 6% 1	180
	21st to end	Day	23% 22% 32% 19% 3 1	198
January	1st to 10th	Night	22% 16% 37% 21% 5%	850
	11th to 20th	Night	22% 18% 33% 21% 5%	785
	21st to end	Night	14% 14% 35% 28% 9%	836
February	1st to 10th	Night	14% 16% 39% 23% 8% 1	760
	11th to 20th	Night	20% 15% 34% 22% 7% 1	743
	21st to end	Night	17% 13% 34% 26% 7% 2	628
March	1st to 10th	Night	19% 14% 31% 27% 8% 1	760
	11th to 20th	Night	25% 15% 29% 21% 9% 1	760
	21st to end	Night	24% 14% 28% 26% 7% 1	836
April	1st to 10th	Night	28% 12% 31% 20% 7% 1	724
	11th to 20th	Night	27% 9% 26% 26% 10% 1	564
	21st to end	Night	29% 9% 26% 25% 10% 1	570
May	1st to 10th	Night	29% 7% 23% 29% 11% 1	570
	11th to 20th	Night	22% 6% 25% 32% 15% 1	423
	21st to end	Night	26% 9% 26% 27% 11% 1	411
June	1st to 10th	Night	22% 6% 21% 37% 13% 1	380
	11th to 20th	Night	22% 7% 20% 35% 15% 2	380
	21st to end	Night	24% 5% 23% 33% 14% 1	380
July	1st to 10th	Night	18% 4 28% 34% 12% 3	370
	11th to 20th	Night	13% 4 26% 41% 15% 1	368
	21st to end	Night	17% 4 21% 39% 17% 1	416
August	1st to 10th	Night	17% 4 22% 37% 18% 2	450
	11th to 20th	Night	19% 2 22% 36% 20% 2	562
	21st to end	Night	18% 4 23% 36% 17% 3	627
September	1st to 10th	Night	20% 6% 25% 32% 15% 1	680
	11th to 20th	Night	23% 6% 26% 30% 13% 3	760
	21st to end	Night	20% 8% 28% 31% 13% 1	760
October	1st to 10th	Night	23% 9% 29% 27% 11% 1	760
	11th to 20th	Night	31% 8% 27% 23% 11% 1	760
	21st to end	Night	29% 15% 26% 22% 8%	836
November	1st to 10th	Night	28% 16% 29% 22% 5%	771
	11th to 20th	Night	27% 20% 27% 19% 6% 1	850
	21st to end	Night	25% 17% 31% 21% 6%	850
December	1st to 10th	Night	27% 16% 31% 19% 6% 1	850
	11th to 20th	Night	25% 20% 29% 20% 5% 1	850
	21st to end	Night	24% 18% 27% 22% 6% 1	935

Page generated at 2024-10-31 03:39:27. Version ac07

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