diff --git a/docs/iris/src/whatsnew/2.2.rst b/docs/iris/src/whatsnew/2.2.rst
index 61a52e3784..1eff99ecb4 100644
--- a/docs/iris/src/whatsnew/2.2.rst
+++ b/docs/iris/src/whatsnew/2.2.rst
@@ -85,8 +85,6 @@ Iris 2.2 Dependency updates
 Bugs Fixed
 ==========
 
-* Cube equality of boolean data is now handled correctly.
-
 * The bug has been fixed that prevented printing time coordinates with bounds
   when the time coordinate was measured on a long interval (that is, ``months``
   or ``years``).
diff --git a/docs/iris/src/whatsnew/contributions_2.3.0/bugfix_2019-Oct-02_boolean_data_compare.txt b/docs/iris/src/whatsnew/contributions_2.3.0/bugfix_2019-Oct-02_boolean_data_compare.txt
new file mode 100644
index 0000000000..332e60c863
--- /dev/null
+++ b/docs/iris/src/whatsnew/contributions_2.3.0/bugfix_2019-Oct-02_boolean_data_compare.txt
@@ -0,0 +1 @@
+* Cube equality of boolean data is now handled correctly.
diff --git a/docs/iris/src/whatsnew/contributions_2.3.0/newfeature_2019-Oct-02_cube_equality_tolerance.txt b/docs/iris/src/whatsnew/contributions_2.3.0/newfeature_2019-Oct-02_cube_equality_tolerance.txt
new file mode 100644
index 0000000000..7a0c15f421
--- /dev/null
+++ b/docs/iris/src/whatsnew/contributions_2.3.0/newfeature_2019-Oct-02_cube_equality_tolerance.txt
@@ -0,0 +1,6 @@
+* Cube data equality testing (and hence cube equality) now uses a more relaxed
+  tolerance : This means that some cubes may now test 'equal' that previously
+  did not.
+  Previously, Iris compared cube data arrays using "abs(a - b) < 1.e-8".
+  We now apply the default operation of :func:`numpy.allclose` instead,
+  which is equivalent to "abs(a - b) < (1.e-8 + 1.e-5 * b)".
diff --git a/lib/iris/tests/unit/cube/test_Cube.py b/lib/iris/tests/unit/cube/test_Cube.py
index 7d02f2d0ca..ea2c3c2dfe 100644
--- a/lib/iris/tests/unit/cube/test_Cube.py
+++ b/lib/iris/tests/unit/cube/test_Cube.py
@@ -1905,5 +1905,51 @@ def test_preserves_lazy(self):
         self.assertArrayAllClose(cube.data, real_data_ft)
 
 
+class Test__eq__data(tests.IrisTest):
+    """Partial cube equality testing, for data type only."""
+    def test_data_float_eq(self):
+        cube1 = Cube([1.0])
+        cube2 = Cube([1.0])
+        self.assertTrue(cube1 == cube2)
+
+    def test_data_float_eqtol(self):
+        val1 = np.array(1.0, dtype=np.float32)
+        # NOTE: Since v2.3, Iris uses "allclose".  Prior to that we used
+        # "rtol=1e-8", and this example would *fail*.
+        val2 = np.array(1.0 + 1.e-6, dtype=np.float32)
+        cube1 = Cube([val1])
+        cube2 = Cube([val2])
+        self.assertNotEqual(val1, val2)
+        self.assertTrue(cube1 == cube2)
+
+    def test_data_float_not_eq(self):
+        val1 = 1.0
+        val2 = 1.0 + 1.e-4
+        cube1 = Cube([1.0, val1])
+        cube2 = Cube([1.0, val2])
+        self.assertFalse(cube1 == cube2)
+
+    def test_data_int_eq(self):
+        cube1 = Cube([1, 2, 3])
+        cube2 = Cube([1, 2, 3])
+        self.assertTrue(cube1 == cube2)
+
+    def test_data_int_not_eq(self):
+        cube1 = Cube([1, 2, 3])
+        cube2 = Cube([1, 2, 0])
+        self.assertFalse(cube1 == cube2)
+
+    # NOTE: since numpy v1.18, boolean array subtract is deprecated.
+    def test_data_bool_eq(self):
+        cube1 = Cube([True, False])
+        cube2 = Cube([True, False])
+        self.assertTrue(cube1 == cube2)
+
+    def test_data_bool_not_eq(self):
+        cube1 = Cube([True, False])
+        cube2 = Cube([True, True])
+        self.assertFalse(cube1 == cube2)
+
+
 if __name__ == '__main__':
     tests.main()
diff --git a/requirements/core.txt b/requirements/core.txt
index eb7d39ca5d..48ee3f1dfd 100644
--- a/requirements/core.txt
+++ b/requirements/core.txt
@@ -7,7 +7,7 @@ cartopy
 #conda: proj4<6
 cf-units>=2
 cftime
-dask[array]>=1.1.0  #conda: dask>=1.1.0
+dask[array]>=1.2.0  #conda: dask>=1.2.0
 matplotlib>=2,<3
 netcdf4
 numpy>=1.14