Qualicum Beach
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Qualicum Beach clear sky chart from 2005-11-06 to 2025-11-18.

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	13% 10% 3 9% 6% 5% 5% 4 5% 7% 34%	131063
	Night	14% 10% 4 9% 6% 5% 5% 4 5% 6% 31%	128033
Transparency	Day	49% 5% 18% 20% 7% 1	130762
	Night	55% 5% 16% 18% 6% 1	127911
Seeing	Day	19% 6% 18% 26% 23% 8%	16972
	Night	24% 6% 17% 26% 21% 6%	24959

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	23% 18% 5% 12% 7% 7% 5% 3 5% 4 11%	3179
	11th to 20th	Day	14% 11% 5% 8% 6% 6% 6% 5% 7% 9% 24%	3159
	21st to end	Day	18% 14% 5% 12% 8% 6% 5% 4 4 4 21%	3913
February	1st to 10th	Day	18% 16% 5% 11% 8% 6% 5% 5% 6% 6% 13%	1800
	11th to 20th	Day	17% 17% 5% 10% 6% 6% 5% 4 5% 5% 20%	1755
	21st to end	Day	15% 15% 5% 10% 8% 6% 6% 5% 5% 7% 18%	1485
March	1st to 10th	Day	11% 17% 5% 13% 8% 7% 7% 5% 6% 5% 16%	4729
	11th to 20th	Day	10% 13% 4 12% 8% 6% 6% 4 5% 7% 23%	5000
	21st to end	Day	18% 15% 5% 12% 8% 7% 6% 4 5% 5% 16%	5517
April	1st to 10th	Day	16% 14% 5% 12% 7% 6% 6% 4 5% 5% 19%	2400
	11th to 20th	Day	14% 13% 4 10% 7% 7% 5% 4 5% 5% 27%	2550
	21st to end	Day	16% 11% 4 10% 6% 5% 5% 5% 6% 6% 27%	2600
May	1st to 10th	Day	11% 8% 3 8% 6% 5% 5% 4 6% 6% 40%	6315
	11th to 20th	Day	12% 9% 3 8% 5% 5% 5% 5% 6% 10% 32%	6277
	21st to end	Day	15% 9% 3 9% 6% 6% 6% 5% 7% 7% 27%	7302
June	1st to 10th	Day	16% 10% 3 8% 7% 7% 5% 4 6% 6% 29%	3000
	11th to 20th	Day	11% 9% 4 11% 7% 6% 7% 5% 7% 8% 26%	3000
	21st to end	Day	10% 8% 4 9% 6% 5% 5% 4 6% 7% 36%	3000
July	1st to 10th	Day	6% 3 1 4 3 3 3 3 4 7% 62%	6780
	11th to 20th	Day	3 3 1 2 2 2 2 2 4 6% 73%	6780
	21st to end	Day	4 3 1 5% 3 3 3 3 5% 8% 62%	7224
August	1st to 10th	Day	5% 3 1 3 2 2 2 2 4 7% 68%	4382
	11th to 20th	Day	9% 8% 3 7% 4 4 4 4 7% 9% 38%	4156
	21st to end	Day	10% 6% 2 8% 4 4 4 4 5% 8% 45%	4647
September	1st to 10th	Day	9% 5% 2 6% 4 4 5% 4 5% 8% 50%	2400
	11th to 20th	Day	14% 7% 2 7% 4 4 4 4 5% 6% 42%	2318
	21st to end	Day	15% 7% 3 8% 5% 4 4 4 6% 6% 36%	2158
October	1st to 10th	Day	14% 10% 4 12% 7% 5% 4 4 6% 7% 29%	3280
	11th to 20th	Day	21% 8% 3 9% 6% 6% 6% 4 5% 6% 26%	3261
	21st to end	Day	14% 10% 5% 12% 8% 7% 6% 5% 6% 6% 21%	3255
November	1st to 10th	Day	20% 15% 5% 12% 6% 7% 6% 4 4 4 17%	1648
	11th to 20th	Day	17% 15% 4 9% 6% 7% 6% 5% 5% 5% 20%	1656
	21st to end	Day	20% 16% 5% 11% 7% 5% 6% 4 5% 5% 17%	1600
December	1st to 10th	Day	11% 13% 5% 12% 8% 7% 8% 5% 5% 6% 20%	2394
	11th to 20th	Day	21% 17% 6% 12% 7% 7% 5% 4 4 4 12%	2645
	21st to end	Day	20% 16% 5% 13% 8% 7% 6% 4 5% 5% 11%	3498
January	1st to 10th	Night	19% 19% 6% 14% 7% 6% 5% 4 4 5% 11%	6766
	11th to 20th	Night	15% 9% 3 10% 6% 4 5% 4 5% 8% 31%	6739
	21st to end	Night	20% 13% 4 9% 6% 5% 5% 3 4 5% 24%	7049
February	1st to 10th	Night	18% 15% 5% 10% 7% 6% 5% 3 5% 5% 22%	2600
	11th to 20th	Night	17% 14% 4 9% 6% 5% 5% 4 4 6% 28%	2532
	21st to end	Night	17% 16% 5% 9% 6% 4 4 4 5% 5% 24%	2145
March	1st to 10th	Night	11% 13% 5% 11% 6% 6% 5% 4 6% 7% 25%	5157
	11th to 20th	Night	8% 10% 3 9% 6% 7% 7% 6% 7% 7% 31%	4999
	21st to end	Night	18% 14% 5% 11% 7% 6% 5% 4 4 5% 21%	5458
April	1st to 10th	Night	15% 11% 4 10% 7% 4 6% 5% 6% 8% 25%	2000
	11th to 20th	Night	13% 11% 4 7% 5% 5% 5% 4 6% 7% 32%	1796
	21st to end	Night	15% 10% 4 8% 7% 4 5% 4 6% 8% 29%	1800
May	1st to 10th	Night	11% 7% 3 6% 4 4 4 3 4 6% 46%	3645
	11th to 20th	Night	11% 6% 3 8% 5% 5% 5% 5% 7% 9% 36%	3616
	21st to end	Night	16% 9% 4 10% 6% 5% 5% 4 6% 6% 28%	3570
June	1st to 10th	Night	13% 8% 4 8% 6% 4 5% 4 6% 6% 38%	1400
	11th to 20th	Night	12% 8% 4 7% 6% 6% 5% 5% 6% 9% 34%	1400
	21st to end	Night	6% 5% 3 7% 6% 5% 6% 5% 8% 9% 41%	1400
July	1st to 10th	Night	4 4 1 4 3 3 3 3 5% 7% 62%	3180
	11th to 20th	Night	2 1 1 1 2 2 2 2 5% 6% 77%	3180
	21st to end	Night	4 3 1 3 2 2 3 4 5% 6% 66%	3617
August	1st to 10th	Night	3 3 1 3 2 2 2 2 4 6% 72%	2770
	11th to 20th	Night	10% 6% 2 7% 5% 4 5% 4 6% 8% 42%	2902
	21st to end	Night	11% 5% 2 5% 4 5% 4 3 5% 7% 48%	3262
September	1st to 10th	Night	7% 4 2 5% 3 3 3 3 4 7% 59%	2000
	11th to 20th	Night	14% 7% 3 6% 5% 5% 4 4 5% 6% 42%	2080
	21st to end	Night	15% 8% 3 7% 5% 4 4 3 4 6% 41%	2241
October	1st to 10th	Night	12% 9% 4 10% 6% 6% 5% 3 4 5% 35%	3920
	11th to 20th	Night	16% 10% 4 10% 5% 6% 5% 4 5% 6% 29%	3897
	21st to end	Night	15% 9% 4 11% 7% 6% 5% 4 6% 7% 28%	4544
November	1st to 10th	Night	21% 12% 4 9% 7% 6% 6% 4 6% 6% 19%	2870
	11th to 20th	Night	19% 12% 5% 11% 7% 6% 5% 4 5% 6% 21%	2898
	21st to end	Night	19% 13% 5% 11% 7% 6% 6% 4 4 5% 20%	2800
December	1st to 10th	Night	12% 13% 5% 12% 10% 8% 6% 4 5% 6% 18%	4782
	11th to 20th	Night	20% 17% 6% 14% 8% 6% 6% 4 5% 4 11%	5560
	21st to end	Night	21% 14% 5% 11% 7% 6% 6% 5% 5% 6% 15%	7458

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	77% 4 7% 10% 2	3179
	11th to 20th	Day	58% 8% 16% 15% 2	3180
	21st to end	Day	69% 4 12% 11% 3	3913
February	1st to 10th	Day	70% 5% 10% 9% 4 1	1800
	11th to 20th	Day	65% 5% 12% 14% 4	1764
	21st to end	Day	63% 5% 14% 12% 6% 1	1485
March	1st to 10th	Day	67% 4 10% 14% 6%	4729
	11th to 20th	Day	58% 4 12% 20% 5%	5000
	21st to end	Day	67% 5% 13% 11% 2	5517
April	1st to 10th	Day	61% 6% 15% 14% 4	2400
	11th to 20th	Day	54% 5% 13% 17% 9% 2	2550
	21st to end	Day	52% 4 15% 20% 8% 1	2600
May	1st to 10th	Day	42% 5% 17% 26% 10% 1	6315
	11th to 20th	Day	44% 7% 23% 23% 4	6280
	21st to end	Day	51% 7% 20% 15% 6%	7303
June	1st to 10th	Day	49% 6% 17% 20% 6% 2	3000
	11th to 20th	Day	46% 6% 24% 19% 4 1	3000
	21st to end	Day	41% 6% 23% 21% 8% 1	3000
July	1st to 10th	Day	22% 5% 22% 28% 18% 5%	6706
	11th to 20th	Day	14% 4 24% 39% 17% 2	6699
	21st to end	Day	20% 6% 33% 29% 12% 1	7020
August	1st to 10th	Day	17% 3 16% 47% 15% 1	4365
	11th to 20th	Day	36% 9% 29% 17% 8% 1	4195
	21st to end	Day	36% 6% 23% 26% 8% 1	4646
September	1st to 10th	Day	31% 7% 24% 27% 11% 2	2400
	11th to 20th	Day	44% 4 19% 21% 11% 1	2318
	21st to end	Day	48% 5% 18% 19% 8% 1	2158
October	1st to 10th	Day	54% 6% 16% 19% 5%	3280
	11th to 20th	Day	60% 5% 13% 18% 3	3261
	21st to end	Day	61% 7% 14% 14% 4	3255
November	1st to 10th	Day	68% 5% 12% 10% 4	1648
	11th to 20th	Day	66% 5% 11% 13% 4 1	1656
	21st to end	Day	72% 5% 10% 8% 5%	1600
December	1st to 10th	Day	64% 8% 12% 13% 3	2394
	11th to 20th	Day	78% 4 9% 7% 2	2648
	21st to end	Day	76% 5% 10% 7% 2	3498
January	1st to 10th	Night	78% 2 8% 9% 3	6766
	11th to 20th	Night	55% 7% 19% 16% 4	6780
	21st to end	Night	67% 6% 11% 14% 2	7049
February	1st to 10th	Night	65% 4 12% 12% 6% 1	2600
	11th to 20th	Night	59% 4 15% 15% 7% 1	2534
	21st to end	Night	61% 5% 11% 16% 6% 1	2145
March	1st to 10th	Night	60% 3 12% 18% 7%	5157
	11th to 20th	Night	51% 4 14% 25% 5%	5000
	21st to end	Night	68% 4 12% 12% 3	5458
April	1st to 10th	Night	57% 5% 16% 17% 5%	2000
	11th to 20th	Night	50% 5% 13% 21% 9% 2	1796
	21st to end	Night	51% 3 16% 20% 9% 1	1800
May	1st to 10th	Night	41% 3 14% 32% 10%	3642
	11th to 20th	Night	43% 7% 24% 21% 4 1	3616
	21st to end	Night	58% 5% 15% 19% 3	3570
June	1st to 10th	Night	47% 5% 19% 20% 8% 2	1400
	11th to 20th	Night	49% 4 22% 21% 5%	1400
	21st to end	Night	40% 5% 23% 23% 7% 2	1400
July	1st to 10th	Night	24% 5% 22% 27% 17% 4	3145
	11th to 20th	Night	12% 4 27% 40% 16% 1	3138
	21st to end	Night	20% 6% 34% 27% 12% 1	3516
August	1st to 10th	Night	16% 2 14% 44% 22% 1	2762
	11th to 20th	Night	38% 8% 28% 16% 8% 2	2929
	21st to end	Night	37% 7% 24% 25% 7% 1	3262
September	1st to 10th	Night	27% 4 21% 33% 13% 3	2000
	11th to 20th	Night	42% 5% 16% 18% 16% 2	2080
	21st to end	Night	46% 4 19% 20% 8% 2	2241
October	1st to 10th	Night	52% 7% 16% 16% 7%	3920
	11th to 20th	Night	55% 5% 16% 20% 4	3897
	21st to end	Night	56% 7% 16% 16% 4	4544
November	1st to 10th	Night	66% 5% 12% 12% 4 1	2870
	11th to 20th	Night	67% 5% 13% 11% 5% 1	2898
	21st to end	Night	67% 4 12% 12% 4 1	2800
December	1st to 10th	Night	66% 7% 12% 11% 3	4782
	11th to 20th	Night	79% 4 9% 6% 2	5556
	21st to end	Night	72% 5% 10% 10% 3	7458

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	33% 7% 27% 21% 7% 6%	200
	11th to 20th	Day	32% 8% 28% 18% 14% 2	200
	21st to end	Day	28% 9% 24% 22% 12% 5%	310
February	1st to 10th	Day	32% 10% 24% 18% 16% 1	400
	11th to 20th	Day	28% 8% 21% 26% 14% 2	395
	21st to end	Day	23% 15% 25% 23% 11% 2	331
March	1st to 10th	Day	23% 10% 19% 25% 19% 4	479
	11th to 20th	Day	24% 7% 20% 25% 19% 4	500
	21st to end	Day	27% 7% 23% 26% 15% 4	550
April	1st to 10th	Day	23% 11% 21% 24% 17% 3	500
	11th to 20th	Day	19% 7% 24% 27% 17% 6%	492
	21st to end	Day	19% 8% 21% 26% 21% 6%	500
May	1st to 10th	Day	13% 4 19% 32% 26% 6%	503
	11th to 20th	Day	17% 4 14% 28% 27% 9%	528
	21st to end	Day	14% 3 17% 31% 26% 9%	738
June	1st to 10th	Day	18% 5% 18% 29% 24% 7%	730
	11th to 20th	Day	11% 6% 21% 29% 24% 9%	730
	21st to end	Day	12% 4 15% 32% 28% 10%	730
July	1st to 10th	Day	11% 3 11% 29% 33% 13%	721
	11th to 20th	Day	6% 2 12% 30% 38% 12%	718
	21st to end	Day	5% 2 10% 30% 37% 17%	731
August	1st to 10th	Day	9% 4 6% 24% 33% 24%	527
	11th to 20th	Day	7% 3 11% 30% 33% 15%	517
	21st to end	Day	10% 3 14% 27% 33% 12%	583
September	1st to 10th	Day	10% 5% 12% 30% 29% 14%	530
	11th to 20th	Day	18% 4 14% 25% 26% 12%	530
	21st to end	Day	21% 5% 19% 28% 20% 6%	530
October	1st to 10th	Day	23% 8% 16% 25% 18% 10%	530
	11th to 20th	Day	28% 5% 21% 21% 18% 7%	530
	21st to end	Day	27% 9% 23% 24% 13% 4	455
November	1st to 10th	Day	29% 11% 26% 22% 12%	220
	11th to 20th	Day	32% 7% 19% 20% 15% 8%	214
	21st to end	Day	36% 8% 20% 19% 12% 6%	200
December	1st to 10th	Day	34% 11% 18% 17% 15% 7%	200
	11th to 20th	Day	35% 11% 20% 23% 12% 1	200
	21st to end	Day	36% 14% 21% 20% 9%	220
January	1st to 10th	Night	35% 10% 22% 20% 11% 3	900
	11th to 20th	Night	34% 7% 15% 23% 19% 2	900
	21st to end	Night	33% 5% 18% 22% 17% 5%	943
February	1st to 10th	Night	29% 7% 21% 25% 15% 3	800
	11th to 20th	Night	27% 5% 19% 26% 21% 2	784
	21st to end	Night	29% 8% 17% 28% 15% 4	660
March	1st to 10th	Night	23% 8% 21% 27% 17% 6%	800
	11th to 20th	Night	24% 7% 22% 23% 19% 4	800
	21st to end	Night	25% 7% 18% 26% 18% 6%	880
April	1st to 10th	Night	22% 8% 15% 30% 20% 6%	800
	11th to 20th	Night	17% 7% 20% 34% 18% 4	608
	21st to end	Night	22% 5% 18% 31% 19% 5%	600
May	1st to 10th	Night	15% 5% 17% 30% 28% 5%	405
	11th to 20th	Night	17% 4 12% 31% 26% 9%	394
	21st to end	Night	14% 5% 17% 31% 27% 6%	433
June	1st to 10th	Night	15% 5% 16% 39% 22% 3	400
	11th to 20th	Night	13% 6% 17% 33% 25% 7%	400
	21st to end	Night	11% 3 12% 35% 32% 7%	400
July	1st to 10th	Night	8% 2 12% 33% 34% 11%	390
	11th to 20th	Night	4 3 13% 34% 34% 11%	388
	21st to end	Night	4 2 7% 37% 38% 12%	438
August	1st to 10th	Night	9% 1 9% 25% 40% 16%	494
	11th to 20th	Night	8% 3 9% 29% 41% 10%	594
	21st to end	Night	11% 3 12% 30% 36% 8%	664
September	1st to 10th	Night	8% 2 11% 33% 35% 12%	800
	11th to 20th	Night	18% 3 11% 20% 30% 18%	800
	21st to end	Night	23% 4 16% 23% 25% 8%	800
October	1st to 10th	Night	20% 5% 14% 26% 27% 8%	800
	11th to 20th	Night	26% 5% 16% 24% 22% 7%	800
	21st to end	Night	28% 7% 20% 27% 16% 4	880
November	1st to 10th	Night	32% 9% 18% 27% 13% 1	820
	11th to 20th	Night	30% 10% 20% 23% 14% 4	828
	21st to end	Night	33% 8% 18% 23% 15% 4	800
December	1st to 10th	Night	31% 8% 16% 22% 20% 4	866
	11th to 20th	Night	37% 8% 22% 21% 10% 1	900
	21st to end	Night	37% 10% 23% 20% 9% 2	990

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