What is the Solunar theory about, and
how can you use it to improve your catch?
Credit for the Solunar Theory goes to John Alden
Knight, the author of "Moon Up...Moon Down" (Solunar Sales
1972), "The Modern Angler: Including the Solunar Theory"
(C. Scribner's Sons, ltd. 1936) and "The Theory and Technique
of Fresh Water Angling" (Harcourt Brace and Company New York
1940. In 1926 , he considered some folk lore that he picked up
while fishing in Florida and decided to evaluate 33 factors which
might influence behavior of fresh or saltwater fishes that caused
them to be periodically more active. Of those, three seemed to
merit further examination: sunrise/sunset, phase of the moon and
tides. From that effort, this avid fly fisherman created the
Solunar Theory (Sol = sun, and Lunar = moon).
Tides had long been known as an important factor in
saltwater fishing success and the connection with moon phase was
well understood. Knight then supposed that the relationship of the
sun and moon, rather than actual tidal stages might be the
determining factor. As his research continued, he determined that
in addition to the time of moon up - moon down there were
intermediate periods of fishing activity that occurred midway
between the two major periods. So he coined the phrases 'major
periods' and 'minor periods' to describe them respectively.
Knight used this information to publish the first
Solunar Tables in 1936. These tables are still widely published and
numerous programs, some on digital watches, emulate them. To be
accurate the precise times from each table must consider the
geographic location and be adjusted for Daylight Savings Time, if
The periods of greatest animal activity (not only
fish are influenced) last from 1.5 to 3 hours depending on the
moon's relationship to the sun. Minor Solunar periods are indicated
during the rising and setting times of the moon, and major periods
are indicated during the two transits. You can roughly calculate
these times for yourself by adding six hours to the rise and set
times for the moon (
Lunar Calculator for an on-line display of the moons phase and
a moonrise/set calculator for any date and location, based on U.S.
Naval Observatory data).
To substantiate this theory, Knight attempted a
systematic inquiry by considering the timing of 200 'record'
catches, more than 90 percent were made during a new moon (when no
moon is visible). This is the time when solunar periods appear
strongest, and they were made during the actual times of the
Because of the interaction between the many lunar
and solar cycles, no two days, months or years are identical. June
has a greater combined solunar influence than any other month.
During a full moon, the sun and moon are nearly opposite each other
and given the length of the day, one or the other is nearly always
above the horizon. During a new moon, both bodies are in
near-perfect rhythm traveling the skies together with their forces
A great way to preview this is to visit the Weather
Skywatch display. Enter a zipcode near where you'll be
fishing and the date you want to fish. The display will simulate
the rise and fall of both the moon and sun and then give you their
exact times and the moon phase. Remember when a maximum solunar
period (six hours after moonrise or moonset) falls within 30-60
minutes of sunrise or sunset you can anticipate great action!
Better still, if the solunar period occurs near dusk or dawn and If
it corresponds with a new or full moon, you can hope for truly
Weather.com also provides links to Recreation
Information for Boating that includes tide data and water
Other factors can greatly affect the predictive
ability of solunar tables. For instance, you should also consider
local weather patterns. Barometric changes, especially a downward
trend, can often ruin fishing. Fish and wildlife have an innate
ability to predict weather and react accordingly. Cold fronts tend
to drive fish deeper and make them active. Conversely, If the
barometer is steady or rising, and the air temperature is
approximately 15 degrees Fahrenheit higher than the water
temperature a more active response to a solunar prediction can be
anticipated. Temperature is also associated with
spawning times and can be a key factor in the seasonal patterns
with which freshwater fish are sought.
Another thing to remember in dealing with Solunar Periods is that
solunar influence will vary in intensity according to the position
of the moon. The times of new moon (the dark of the moon), and full
moon are the times of maximum intensity (See: Lunar
Calculator for a visual monthly display, or the naval
observatory has online records of moon
phases). Ocean tides reflect this intensity in their magnitude.
This maximum will last about three days, and wildlife respond with
maximum activity. Thereafter the degree of intensity tapers off
until it is at its minimum during the third quarter phase of the
Some salt-water anglers argue that tides have more influence on
fish feeding habits than the moon itself. It must be understood
that the tides are governed by the phases and transit of the moon.
Certain marine phenomena occur with precise regularity during the
lunar month and solar/lunar cycle.
Research has shown that a natural day for fish and many other
animal species is based on a diurnal (twice daily) 'biological
clock' that appears to coincide with lunar time. In other words its
is based on the time that it takes the moon to complete one
rotation of the earth (an average of 24 hours and 53 minutes). This
is also called a 'tidal day' and explains why ocean tides are about
an hour later each day - and why most fish, fresh water species
included, will feed up to an hour later (in relation to our solar
clock) each day.
Remember ... the BEST time to go fishin' ... is whenever you can
Note: This article is derived from a variety of
online sources including the Naval Observatory and www.solunar.com