Moon Phases and Bass Fishing
I took the Texas top 50 bass and looked up the moon phase for each date and noted some interesting statistics. 23 of the top 50 were caught with at least 75% illumination, meaning they were close to a full moon. Only a fourth of the time is it 75% or more illumination. So almost half of the top 50 bass in Texas were caught in a fourth of the time. Could it be coincidence?
I did the same analysis with my personal top 50 and yielded similar results. 21 of my top 50 were caught with at least 75% moon.
Another observation I have noticed is that the full moon has less influence in the summer than other seasons. In fact, there is not a single entry in either the Texas top 50 or my own personal top 50 around the full moon in the summer. Of course, this is due partly because fish are not as big in summer as they are spring and winter, but there is a handful of top 50 entries around new or half moons in the summer - just not around the full moon. Based on this, I recommend fishing the half moon instead of the full moon if you fish in the summer and have the choice.
During the spawn, you hear a lot about the full moon bringing out new waves of fish on the beds. I have seen it happen and I have also seen it not happen. I can recall a time recently when my worst day in April was the day of the full moon. However, you can't deny the fact that a large number of big fish are caught around the full moon in the spring. Does that mean that we should only fish around the full moon in the spring? I don't think so! Those statistics are somewhat skewed because some people have to plan their trips in advance and plan them around the full moons. So, it is likely that more people are fishing around the full moon than other times. Also, I have found that monster bass are different creatures than smaller bass - even 8 and 9 pound bass. I often catch my biggest bass when the fishing is slow. So, fishing when the potential for bigger fish is best may not be the best time to catch lots of fish. You also have to consider factors that are more important than moon phases. Some examples are seasonal patterns, water temps, time of day, water clarity, cloud cover, etc.
In September 2003, I started giving my trips a rating of 0 to 100 based on how I thought we did. That rating is subjective, but since it is the same person rating all the trips, it should give a reasonably accurate rating throughout the year (or years). In June 2004, I decided to include another rating which I believe should be even more accurate. I call this a "potential" rating. I believe it should be more accurate because it is based on how the fish were biting, not how many we boated. If we lost some fish or if I saw other fishermen catching fish, the "potential" rating may be higher than my trip rating.
On 1/5/2013, I ran a query based on those ratings and discovered that moon phases had very little influence on my overall catch.
Here's my results:
| Rating | Potential Rating | |
| <34% moon | 51% | 56% |
| 34-65% moon | 51% | 56% |
| >66% moon | 52% | 58% |
Below is a query with the months added. This may be interesting for the statistic guru.
| mth | Phase | TripRating | Potential |
|---|---|---|---|
| 1 | full | 37.8571428571429 | 38.5714285714286 |
| 1 | half | 35 | 55 |
| 1 | new | 52.2222222222222 | 52.2222222222222 |
| 2 | full | 54.5454545454545 | 58.1818181818182 |
| 2 | half | 53.5714285714286 | 53.5714285714286 |
| 2 | new | 55.625 | 58.125 |
| 3 | full | 52.5 | 60.1388888888889 |
| 3 | half | 47.8260869565217 | 51.304347826087 |
| 3 | new | 49.6590909090909 | 56.25 |
| 4 | full | 48.5227272727273 | 58.6363636363636 |
| 4 | half | 51.6666666666667 | 62.9166666666667 |
| 4 | new | 56.046511627907 | 66.7441860465116 |
| 5 | full | 51.5789473684211 | 58.6842105263158 |
| 5 | half | 57.2727272727273 | 64.0909090909091 |
| 5 | new | 52.6315789473684 | 57.3684210526316 |
| 6 | full | 51.7441860465116 | 56.046511627907 |
| 6 | half | 56.25 | 59.6875 |
| 6 | new | 47.2222222222222 | 51.1538461538462 |
| 7 | full | 56.6 | 66 |
| 7 | half | 40 | 46.6666666666667 |
| 7 | new | 35 | 40.7142857142857 |
| 8 | full | 54.7222222222222 | 62.5 |
| 8 | half | 39 | 41 |
| 8 | new | 43.8888888888889 | 52.2222222222222 |
| 9 | full | 65 | 71 |
| 9 | half | 45 | 47.5 |
| 9 | new | 43.75 | 46.25 |
| 10 | full | 52.9166666666667 | 54.5833333333333 |
| 10 | half | 46.3636363636364 | 47.2727272727273 |
| 10 | new | 53.8888888888889 | 57.7777777777778 |
| 11 | full | 62 | 63.5 |
| 11 | half | 61.5 | 65 |
| 11 | new | 57.1428571428571 | 62.8571428571429 |
| 12 | full | 36.6666666666667 | 43.3333333333333 |
| 12 | half | 65 | 65 |
| 12 | new | 52.5 | 53.5 |